Base station measurement associated with a round-trip time measurement procedure between a user equipment and a different base station

ABSTRACT

In an aspect, a first BS measures a SRS-P associated with a RTT measurement procedure between a UE and a second base station, and reports measurement information based on the measurement of the SRS-P. In another aspect, a device (e.g., UE, BS, LMF, etc.) obtains the measurement information along with measurement information based on measurements at the UE and the second base station, and determines a positioning estimate of the UE based on the first, second and third measurement information.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application for patent claims the benefit of U.S.Provisional Application No. 63/075,549, entitled “BASE STATIONMEASUREMENT ASSOCIATED WITH A ROUND-TRIP TIME MEASUREMENT PROCEDUREBETWEEN A USER EQUIPMENT AND A DIFFERENT BASE STATION,” filed Sep. 8,2020, assigned to the assignee hereof, and expressly incorporated hereinby reference in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

Aspects of the disclosure relate generally to wireless communications,and more particularly to a base station measurement associated with around-trip time (RTT) measurement procedure between a user equipment(UE) and a different base station.

2. Description of the Related Art

Wireless communication systems have developed through variousgenerations, including a first-generation analog wireless phone service(1G), a second-generation (2G) digital wireless phone service (includinginterim 2.5G networks), a third-generation (3G) high speed data,Internet-capable wireless service and a fourth-generation (4G) service(e.g., LTE or WiMax). There are presently many different types ofwireless communication systems in use, including cellular and personalcommunications service (PCS) systems. Examples of known cellular systemsinclude the cellular analog advanced mobile phone system (AMPS), anddigital cellular systems based on code division multiple access (CDMA),frequency division multiple access (FDMA), time division multiple access(TDMA), the Global System for Mobile access (GSM) variation of TDMA,etc.

A fifth generation (5G) wireless standard, referred to as New Radio(NR), enables higher data transfer speeds, greater numbers ofconnections, and better coverage, among other improvements. The 5Gstandard, according to the Next Generation Mobile Networks Alliance, isdesigned to provide data rates of several tens of megabits per second toeach of tens of thousands of users, with 1 gigabit per second to tens ofworkers on an office floor. Several hundreds of thousands ofsimultaneous connections should be supported in order to support largewireless sensor deployments. Consequently, the spectral efficiency of 5Gmobile communications should be significantly enhanced compared to thecurrent 4G standard. Furthermore, signaling efficiencies should beenhanced and latency should be substantially reduced compared to currentstandards.

SUMMARY

The following presents a simplified summary relating to one or moreaspects disclosed herein. Thus, the following summary should not beconsidered an extensive overview relating to all contemplated aspects,nor should the following summary be considered to identify key orcritical elements relating to all contemplated aspects or to delineatethe scope associated with any particular aspect. Accordingly, thefollowing summary has the sole purpose to present certain conceptsrelating to one or more aspects relating to the mechanisms disclosedherein in a simplified form to precede the detailed descriptionpresented below.

In an aspect, a method of operating a first base station includesmeasuring a sounding reference signal for positioning (SRS-P) associatedwith a round-trip time (RTT) measurement procedure between a userequipment (UE) and a second base station; and reporting measurementinformation based on the measurement of the SRS-P.

In some aspects, the method includes measuring a positioning referencesignal (PRS) associated with the RTT measurement procedure.

In some aspects, the measurement information comprises a differencebetween a first time of arrival (ToA) of the SRS-P at the first basestation and a second ToA of the PRS at the first base station.

In some aspects, the PRS follows the SRS-P, or the SRS-P follows thePRS.

In some aspects, the reported measurement information comprises a timeof arrival (ToA) of the SRS-P.

In some aspects, the measurement information comprises a differencebetween a first time of arrival (ToA) of the SRS-P at the first basestation and a second ToA of a positioning reference signal (PRS) at thefirst base station.

In some aspects, the ToA of the PRS at the first base station isestimated based on a known time of PRS transmission and a knownpropagation delay between the first base station and the second basestation.

In some aspects, the reporting reports the measurement information tothe UE, the first base station, a location management function (LMF)component, or a combination thereof.

In an aspect, a method of operating a device includes obtaining firstmeasurement information, based on one or more measurements by at leastone first base station, related to both a positioning reference signal(PRS) associated with a round-trip time (RTT) measurement procedurebetween a user equipment (UE) and a second base station and a soundingreference signal for positioning (SRS-P) from the UE; obtaining secondmeasurement information, based on one or more measurements at the UE,related to the PRS associated with the RTT measurement procedure;obtaining third measurement information, based on one or moremeasurements at the second base station, related to the SRS-P associatedwith the RTT procedure; and determining a positioning estimate of the UEbased on the first, second and third measurement information.

In some aspects, the at least one first base station comprises a singlebase station, or the at least one first base station comprises aplurality of base stations.

In some aspects, the first measurement information is further based onone or more additional measurements by the at least one first basestation related to the PRS associated with the RTT procedure.

In some aspects, the first measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at the atleast one first base station and a second ToA of the PRS at the at leastone first base station.

In some aspects, the PRS follows the SRS-P, or the SRS-P follows thePRS.

In some aspects, the first measurement information comprises a time ofarrival (ToA) of the SRS-P.

In some aspects, the first measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at the atleast one first base station and a second ToA of the PRS at the at leastone first base station.

In some aspects, the ToA of the PRS at the at least one first basestation is estimated based on a known time of PRS transmission and atleast one known propagation delay between the at least one first basestation and the second base station.

In some aspects, the device corresponds to the UE, the first basestation, a location management function (LMF) component, or acombination thereof.

In an aspect, a first base station includes a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: measure a sounding reference signal for positioning(SRS-P) associated with a round-trip time (RTT) measurement procedurebetween a user equipment (UE) and a second base station; and reportmeasurement information based on the measurement of the SRS-P.

In some aspects, the at least one processor is further configured to:measure a positioning reference signal (PRS) associated with the RTTmeasurement procedure.

In some aspects, the measurement information comprises a differencebetween a first time of arrival (ToA) of the SRS-P at the first basestation and a second ToA of the PRS at the first base station.

In some aspects, the PRS follows the SRS-P, or the SRS-P follows thePRS.

In some aspects, the reported measurement information comprises a timeof arrival (ToA) of the SRS-P.

In some aspects, the measurement information comprises a differencebetween a first time of arrival (ToA) of the SRS-P at the first basestation and a second ToA of a positioning reference signal (PRS) at thefirst base station.

In some aspects, the ToA of the PRS at the first base station isestimated based on a known time of PRS transmission and a knownpropagation delay between the first base station and the second basestation.

In some aspects, the reporting reports the measurement information tothe UE, the first base station, a location management function (LMF)component, or a combination thereof.

In an aspect, a device includes a memory; at least one transceiver; andat least one processor communicatively coupled to the memory and the atleast one transceiver, the at least one processor configured to: obtainfirst measurement information, based on one or more measurements by atleast one first base station, related to both a positioning referencesignal (PRS) associated with a round-trip time (RTT) measurementprocedure between a user equipment (UE) and a second base station and asounding reference signal for positioning (SRS-P) from the UE; obtainsecond measurement information, based on one or more measurements at theUE, related to the PRS associated with the RTT measurement procedure;obtain third measurement information, based on one or more measurementsat the second base station, related to the SRS-P associated with the RTTprocedure; and determine a positioning estimate of the UE based on thefirst, second and third measurement information.

In some aspects, the at least one first base station comprises a singlebase station, or the at least one first base station comprises aplurality of base stations.

In some aspects, the first measurement information is further based onone or more additional measurements by the at least one first basestation related to the PRS associated with the RTT procedure.

In some aspects, the first measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at the atleast one first base station and a second ToA of the PRS at the at leastone first base station.

In some aspects, the PRS follows the SRS-P, or the SRS-P follows thePRS.

In some aspects, the first measurement information comprises a time ofarrival (ToA) of the SRS-P.

In some aspects, the first measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at the atleast one first base station and a second ToA of the PRS at the at leastone first base station.

In some aspects, the ToA of the PRS at the at least one first basestation is estimated based on a known time of PRS transmission and atleast one known propagation delay between the at least one first basestation and the second base station.

In some aspects, the device corresponds to the UE, the first basestation, a location management function (LMF) component, or acombination thereof.

In an aspect, a first base station includes means for measuring asounding reference signal for positioning (SRS-P) associated with around-trip time (RTT) measurement procedure between a user equipment(UE) and a second base station; and means for reporting measurementinformation based on the measurement of the SRS-P.

In some aspects, the method includes means for measuring a positioningreference signal (PRS) associated with the RTT measurement procedure.

In some aspects, the measurement information comprises a differencebetween a first time of arrival (ToA) of the SRS-P at the first basestation and a second ToA of the PRS at the first base station.

In some aspects, the PRS follows the SRS-P, or the SRS-P follows thePRS.

In some aspects, the reported measurement information comprises a timeof arrival (ToA) of the SRS-P.

In some aspects, the measurement information comprises a differencebetween a first time of arrival (ToA) of the SRS-P at the first basestation and a second ToA of a positioning reference signal (PRS) at thefirst base station.

In some aspects, the ToA of the PRS at the first base station isestimated based on a known time of PRS transmission and a knownpropagation delay between the first base station and the second basestation.

In some aspects, the reporting reports the measurement information tothe UE, the first base station, a location management function (LMF)component, or a combination thereof.

In an aspect, a device includes means for obtaining first measurementinformation, based on one or more measurements by at least one firstbase station, related to both a positioning reference signal (PRS)associated with a round-trip time (RTT) measurement procedure between auser equipment (UE) and a second base station and a sounding referencesignal for positioning (SRS-P) from the UE; means for obtaining secondmeasurement information, based on one or more measurements at the UE,related to the PRS associated with the RTT measurement procedure; meansfor obtaining third measurement information, based on one or moremeasurements at the second base station, related to the SRS-P associatedwith the RTT procedure; and means for determining a positioning estimateof the UE based on the first, second and third measurement information.

In some aspects, the at least one first base station comprises a singlebase station, or the at least one first base station comprises aplurality of base stations.

In some aspects, the first measurement information is further based onone or more additional measurements by the at least one first basestation related to the PRS associated with the RTT procedure.

In some aspects, the first measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at the atleast one first base station and a second ToA of the PRS at the at leastone first base station.

In some aspects, the PRS follows the SRS-P, or the SRS-P follows thePRS.

In some aspects, the first measurement information comprises a time ofarrival (ToA) of the SRS-P.

In some aspects, the first measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at the atleast one first base station and a second ToA of the PRS at the at leastone first base station.

In some aspects, the ToA of the PRS at the at least one first basestation is estimated based on a known time of PRS transmission and atleast one known propagation delay between the at least one first basestation and the second base station.

In some aspects, the device corresponds to the UE, the first basestation, a location management function (LMF) component, or acombination thereof.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a first basestation, cause the first base station to: measure a sounding referencesignal for positioning (SRS-P) associated with a round-trip time (RTT)measurement procedure between a user equipment (UE) and a second basestation; and report measurement information based on the measurement ofthe SRS-P.

In some aspects, the one or more instructions further cause the firstbase station to: measure a positioning reference signal (PRS) associatedwith the RTT measurement procedure.

In some aspects, the measurement information comprises a differencebetween a first time of arrival (ToA) of the SRS-P at the first basestation and a second ToA of the PRS at the first base station.

In some aspects, the PRS follows the SRS-P, or the SRS-P follows thePRS.

In some aspects, the reported measurement information comprises a timeof arrival (ToA) of the SRS-P.

In some aspects, the measurement information comprises a differencebetween a first time of arrival (ToA) of the SRS-P at the first basestation and a second ToA of a positioning reference signal (PRS) at thefirst base station.

In some aspects, the ToA of the PRS at the first base station isestimated based on a known time of PRS transmission and a knownpropagation delay between the first base station and the second basestation.

In some aspects, the reporting reports the measurement information tothe UE, the first base station, a location management function (LMF)component, or a combination thereof.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a device, causethe device to: obtain first measurement information, based on one ormore measurements by at least one first base station, related to both apositioning reference signal (PRS) associated with a round-trip time(RTT) measurement procedure between a user equipment (UE) and a secondbase station and a sounding reference signal for positioning (SRS-P)from the UE; obtain second measurement information, based on one or moremeasurements at the UE, related to the PRS associated with the RTTmeasurement procedure; obtain third measurement information, based onone or more measurements at the second base station, related to theSRS-P associated with the RTT procedure; and determine a positioningestimate of the UE based on the first, second and third measurementinformation.

In some aspects, the at least one first base station comprises a singlebase station, or the at least one first base station comprises aplurality of base stations.

In some aspects, the first measurement information is further based onone or more additional measurements by the at least one first basestation related to the PRS associated with the RTT procedure.

In some aspects, the first measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at the atleast one first base station and a second ToA of the PRS at the at leastone first base station.

In some aspects, the PRS follows the SRS-P, or the SRS-P follows thePRS.

In some aspects, the first measurement information comprises a time ofarrival (ToA) of the SRS-P.

In some aspects, the first measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at the atleast one first base station and a second ToA of the PRS at the at leastone first base station.

In some aspects, the ToA of the PRS at the at least one first basestation is estimated based on a known time of PRS transmission and atleast one known propagation delay between the at least one first basestation and the second base station.

In some aspects, the device corresponds to the UE, the first basestation, a location management function (LMF) component, or acombination thereof.

Other objects and advantages associated with the aspects disclosedherein will be apparent to those skilled in the art based on theaccompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description ofvarious aspects of the disclosure and are provided solely forillustration of the aspects and not limitation thereof.

FIG. 1 illustrates an exemplary wireless communications system,according to various aspects.

FIGS. 2A and 2B illustrate example wireless network structures,according to various aspects.

FIGS. 3A to 3C are simplified block diagrams of several sample aspectsof components that may be employed in wireless communication nodes andconfigured to support communication as taught herein.

FIGS. 4A and 4B are diagrams illustrating examples of frame structuresand channels within the frame structures, according to aspects of thedisclosure.

FIG. 5 illustrates an exemplary PRS configuration for a cell supportedby a wireless node.

FIG. 6 illustrates an exemplary wireless communications system accordingto various aspects of the disclosure.

FIG. 7 illustrates an exemplary wireless communications system accordingto various aspects of the disclosure.

FIG. 8A is a graph showing the RF channel response at a receiver overtime according to aspects of the disclosure.

FIG. 8B is a diagram illustrating this separation of clusters in AoD.

FIG. 9 is a diagram showing exemplary timings of RTT measurement signalsexchanged between a base station and a UE, according to aspects of thedisclosure.

FIG. 10 illustrates a PRS muting scheme in accordance with an aspect ofthe disclosure.

FIG. 11 illustrates a PRS muting scheme in accordance with an aspect ofthe disclosure

FIG. 12A illustrates an exemplary process of wireless communication,according to aspects of the disclosure.

FIG. 12B illustrates an exemplary process of wireless communication,according to aspects of the disclosure.

FIG. 13A illustrates an exemplary process of wireless communication,according to aspects of the disclosure.

FIG. 13B illustrates an exemplary process of wireless communication,according to aspects of the disclosure.

FIG. 14 is a diagram showing exemplary timings of RTT measurementsignals exchanged between BSs and a UE in accordance with an exampleimplementation of the processes of FIGS. 12A-13B.

FIG. 15 is a diagram showing exemplary timings of RTT measurementsignals exchanged between BSs and a UE in accordance with anotherexample implementation of the processes of FIGS. 12A-13B.

DETAILED DESCRIPTION

Aspects of the disclosure are provided in the following description andrelated drawings directed to various examples provided for illustrationpurposes. Alternate aspects may be devised without departing from thescope of the disclosure. Additionally, well-known elements of thedisclosure will not be described in detail or will be omitted so as notto obscure the relevant details of the disclosure.

The words “exemplary” and/or “example” are used herein to mean “servingas an example, instance, or illustration.” Any aspect described hereinas “exemplary” and/or “example” is not necessarily to be construed aspreferred or advantageous over other aspects. Likewise, the term“aspects of the disclosure” does not require that all aspects of thedisclosure include the discussed feature, advantage or mode ofoperation.

Those of skill in the art will appreciate that the information andsignals described below may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the description below may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof, depending inpart on the particular application, in part on the desired design, inpart on the corresponding technology, etc.

Further, many aspects are described in terms of sequences of actions tobe performed by, for example, elements of a computing device. It will berecognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, the sequence(s)of actions described herein can be considered to be embodied entirelywithin any form of non-transitory computer-readable storage mediumhaving stored therein a corresponding set of computer instructions that,upon execution, would cause or instruct an associated processor of adevice to perform the functionality described herein. Thus, the variousaspects of the disclosure may be embodied in a number of differentforms, all of which have been contemplated to be within the scope of theclaimed subject matter. In addition, for each of the aspects describedherein, the corresponding form of any such aspects may be describedherein as, for example, “logic configured to” perform the describedaction.

As used herein, the terms “user equipment” (UE) and “base station” arenot intended to be specific or otherwise limited to any particular radioaccess technology (RAT), unless otherwise noted. In general, a UE may beany wireless communication device (e.g., a mobile phone, router, tabletcomputer, laptop computer, tracking device, wearable (e.g., smartwatch,glasses, augmented reality (AR)/virtual reality (VR) headset, etc.),vehicle (e.g., automobile, motorcycle, bicycle, etc.), Internet ofThings (IoT) device, etc.) used by a user to communicate over a wirelesscommunications network. A UE may be mobile or may (e.g., at certaintimes) be stationary, and may communicate with a radio access network(RAN). As used herein, the term “UE” may be referred to interchangeablyas an “access terminal” or “AT,” a “client device,” a “wireless device,”a “subscriber device,” a “subscriber terminal,” a “subscriber station,”a “user terminal” or UT, a “mobile terminal,” a “mobile station,” orvariations thereof. Generally, UEs can communicate with a core networkvia a RAN, and through the core network the UEs can be connected withexternal networks such as the Internet and with other UEs. Of course,other mechanisms of connecting to the core network and/or the Internetare also possible for the UEs, such as over wired access networks,wireless local area network (WLAN) networks (e.g., based on IEEE 802.11,etc.) and so on.

A base station may operate according to one of several RATs incommunication with UEs depending on the network in which it is deployed,and may be alternatively referred to as an access point (AP), a networknode, a NodeB, an evolved NodeB (eNB), a New Radio (NR) Node B (alsoreferred to as a gNB or gNodeB), etc. In addition, in some systems abase station may provide purely edge node signaling functions while inother systems it may provide additional control and/or networkmanagement functions. In some systems, a base station may correspond toa Customer Premise Equipment (CPE) or a road-side unit (RSU). In somedesigns, a base station may correspond to a high-powered UE (e.g., avehicle UE or VUE) that may provide limited certain infrastructurefunctionality. A communication link through which UEs can send signalsto a base station is called an uplink (UL) channel (e.g., a reversetraffic channel, a reverse control channel, an access channel, etc.). Acommunication link through which the base station can send signals toUEs is called a downlink (DL) or forward link channel (e.g., a pagingchannel, a control channel, a broadcast channel, a forward trafficchannel, etc.). As used herein the term traffic channel (TCH) can referto either an UL/reverse or DL/forward traffic channel.

The term “base station” may refer to a single physicaltransmission-reception point (TRP) or to multiple physical TRPs that mayor may not be co-located. For example, where the term “base station”refers to a single physical TRP, the physical TRP may be an antenna ofthe base station corresponding to a cell of the base station. Where theterm “base station” refers to multiple co-located physical TRPs, thephysical TRPs may be an array of antennas (e.g., as in a multiple-inputmultiple-output (MIMO) system or where the base station employsbeamforming) of the base station. Where the term “base station” refersto multiple non-co-located physical TRPs, the physical TRPs may be adistributed antenna system (DAS) (a network of spatially separatedantennas connected to a common source via a transport medium) or aremote radio head (RRH) (a remote base station connected to a servingbase station). Alternatively, the non-co-located physical TRPs may bethe serving base station receiving the measurement report from the UEand a neighbor base station whose reference RF signals the UE ismeasuring. Because a TRP is the point from which a base stationtransmits and receives wireless signals, as used herein, references totransmission from or reception at a base station are to be understood asreferring to a particular TRP of the base station.

An “RF signal” comprises an electromagnetic wave of a given frequencythat transports information through the space between a transmitter anda receiver. As used herein, a transmitter may transmit a single “RFsignal” or multiple “RF signals” to a receiver. However, the receivermay receive multiple “RF signals” corresponding to each transmitted RFsignal due to the propagation characteristics of RF signals throughmultipath channels. The same transmitted RF signal on different pathsbetween the transmitter and receiver may be referred to as a “multipath”RF signal.

According to various aspects, FIG. 1 illustrates an exemplary wirelesscommunications system 100. The wireless communications system 100 (whichmay also be referred to as a wireless wide area network (WWAN)) mayinclude various base stations 102 and various UEs 104. The base stations102 may include macro cell base stations (high power cellular basestations) and/or small cell base stations (low power cellular basestations). In an aspect, the macro cell base station may include eNBswhere the wireless communications system 100 corresponds to an LTEnetwork, or gNBs where the wireless communications system 100corresponds to a NR network, or a combination of both, and the smallcell base stations may include femtocells, picocells, microcells, etc.

The base stations 102 may collectively form a RAN and interface with acore network 170 (e.g., an evolved packet core (EPC) or next generationcore (NGC)) through backhaul links 122, and through the core network 170to one or more location servers 172. In addition to other functions, thebase stations 102 may perform functions that relate to one or more oftransferring user data, radio channel ciphering and deciphering,integrity protection, header compression, mobility control functions(e.g., handover, dual connectivity), inter-cell interferencecoordination, connection setup and release, load balancing, distributionfor non-access stratum (NAS) messages, NAS node selection,synchronization, RAN sharing, multimedia broadcast multicast service(MBMS), subscriber and equipment trace, RAN information management(RIM), paging, positioning, and delivery of warning messages. The basestations 102 may communicate with each other directly or indirectly(e.g., through the EPC/NGC) over backhaul links 134, which may be wiredor wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. In an aspect, one or more cellsmay be supported by a base station 102 in each coverage area 110. A“cell” is a logical communication entity used for communication with abase station (e.g., over some frequency resource, referred to as acarrier frequency, component carrier, carrier, band, or the like), andmay be associated with an identifier (e.g., a physical cell identifier(PCI), a virtual cell identifier (VCI)) for distinguishing cellsoperating via the same or a different carrier frequency. In some cases,different cells may be configured according to different protocol types(e.g., machine-type communication (MTC), narrowband IoT (NB-IoT),enhanced mobile broadband (eMBB), or others) that may provide access fordifferent types of UEs. Because a cell is supported by a specific basestation, the term “cell” may refer to either or both the logicalcommunication entity and the base station that supports it, depending onthe context. In some cases, the term “cell” may also refer to ageographic coverage area of a base station (e.g., a sector), insofar asa carrier frequency can be detected and used for communication withinsome portion of geographic coverage areas 110.

While neighboring macro cell base station 102 geographic coverage areas110 may partially overlap (e.g., in a handover region), some of thegeographic coverage areas 110 may be substantially overlapped by alarger geographic coverage area 110. For example, a small cell basestation 102′ may have a coverage area 110′ that substantially overlapswith the coverage area 110 of one or more macro cell base stations 102.A network that includes both small cell and macro cell base stations maybe known as a heterogeneous network. A heterogeneous network may alsoinclude home eNBs (HeNBs), which may provide service to a restrictedgroup known as a closed subscriber group (CSG).

The communication links 120 between the base stations 102 and the UEs104 may include UL (also referred to as reverse link) transmissions froma UE 104 to a base station 102 and/or downlink (DL) (also referred to asforward link) transmissions from a base station 102 to a UE 104. Thecommunication links 120 may use MIMO antenna technology, includingspatial multiplexing, beamforming, and/or transmit diversity. Thecommunication links 120 may be through one or more carrier frequencies.Allocation of carriers may be asymmetric with respect to DL and UL(e.g., more or less carriers may be allocated for DL than for UL).

The wireless communications system 100 may further include a wirelesslocal area network (WLAN) access point (AP) 150 in communication withWLAN stations (STAs) 152 via communication links 154 in an unlicensedfrequency spectrum (e.g., 5 GHz). When communicating in an unlicensedfrequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may performa clear channel assessment (CCA) or listen before talk (LBT) procedureprior to communicating in order to determine whether the channel isavailable.

The small cell base station 102′ may operate in a licensed and/or anunlicensed frequency spectrum. When operating in an unlicensed frequencyspectrum, the small cell base station 102′ may employ LTE or NRtechnology and use the same 5 GHz unlicensed frequency spectrum as usedby the WLAN AP 150. The small cell base station 102′, employing LTE/5Gin an unlicensed frequency spectrum, may boost coverage to and/orincrease capacity of the access network. NR in unlicensed spectrum maybe referred to as NR-U. LTE in an unlicensed spectrum may be referred toas LTE-U, licensed assisted access (LAA), or MulteFire.

The wireless communications system 100 may further include a millimeterwave (mmW) base station 180 that may operate in mmW frequencies and/ornear mmW frequencies in communication with a UE 182. Extremely highfrequency (EHF) is part of the RF in the electromagnetic spectrum. EHFhas a range of 30 GHz to 300 GHz and a wavelength between 1 millimeterand 10 millimeters. Radio waves in this band may be referred to as amillimeter wave. Near mmW may extend down to a frequency of 3 GHz with awavelength of 100 millimeters. The super high frequency (SHF) bandextends between 3 GHz and 30 GHz, also referred to as centimeter wave.Communications using the mmW/near mmW radio frequency band have highpath loss and a relatively short range. The mmW base station 180 and theUE 182 may utilize beamforming (transmit and/or receive) over a mmWcommunication link 184 to compensate for the extremely high path lossand short range. Further, it will be appreciated that in alternativeconfigurations, one or more base stations 102 may also transmit usingmmW or near mmW and beamforming. Accordingly, it will be appreciatedthat the foregoing illustrations are merely examples and should not beconstrued to limit the various aspects disclosed herein.

Transmit beamforming is a technique for focusing an RF signal in aspecific direction. Traditionally, when a network node (e.g., a basestation) broadcasts an RF signal, it broadcasts the signal in alldirections (omni-directionally). With transmit beamforming, the networknode determines where a given target device (e.g., a UE) is located(relative to the transmitting network node) and projects a strongerdownlink RF signal in that specific direction, thereby providing afaster (in terms of data rate) and stronger RF signal for the receivingdevice(s). To change the directionality of the RF signal whentransmitting, a network node can control the phase and relativeamplitude of the RF signal at each of the one or more transmitters thatare broadcasting the RF signal. For example, a network node may use anarray of antennas (referred to as a “phased array” or an “antennaarray”) that creates a beam of RF waves that can be “steered” to pointin different directions, without actually moving the antennas.Specifically, the RF current from the transmitter is fed to theindividual antennas with the correct phase relationship so that theradio waves from the separate antennas add together to increase theradiation in a desired direction, while cancelling to suppress radiationin undesired directions.

Transmit beams may be quasi-collocated, meaning that they appear to thereceiver (e.g., a UE) as having the same parameters, regardless ofwhether or not the transmitting antennas of the network node themselvesare physically collocated. In NR, there are four types ofquasi-collocation (QCL) relations. Specifically, a QCL relation of agiven type means that certain parameters about a second reference RFsignal on a second beam can be derived from information about a sourcereference RF signal on a source beam. Thus, if the source reference RFsignal is QCL Type A, the receiver can use the source reference RFsignal to estimate the Doppler shift, Doppler spread, average delay, anddelay spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type B, the receivercan use the source reference RF signal to estimate the Doppler shift andDoppler spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type C, the receivercan use the source reference RF signal to estimate the Doppler shift andaverage delay of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type D, the receivercan use the source reference RF signal to estimate the spatial receiveparameter of a second reference RF signal transmitted on the samechannel.

In receive beamforming, the receiver uses a receive beam to amplify RFsignals detected on a given channel. For example, the receiver canincrease the gain setting and/or adjust the phase setting of an array ofantennas in a particular direction to amplify (e.g., to increase thegain level of) the RF signals received from that direction. Thus, when areceiver is said to beamform in a certain direction, it means the beamgain in that direction is high relative to the beam gain along otherdirections, or the beam gain in that direction is the highest comparedto the beam gain in that direction of all other receive beams availableto the receiver. This results in a stronger received signal strength(e.g., reference signal received power (RSRP), reference signal receivedquality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) ofthe RF signals received from that direction.

Receive beams may be spatially related. A spatial relation means thatparameters for a transmit beam for a second reference signal can bederived from information about a receive beam for a first referencesignal. For example, a UE may use a particular receive beam to receive areference downlink reference signal (e.g., synchronization signal block(SSB)) from a base station. The UE can then form a transmit beam forsending an uplink reference signal (e.g., sounding reference signal(SRS)) to that base station based on the parameters of the receive beam.

Note that a “downlink” beam may be either a transmit beam or a receivebeam, depending on the entity forming it. For example, if a base stationis forming the downlink beam to transmit a reference signal to a UE, thedownlink beam is a transmit beam. If the UE is forming the downlinkbeam, however, it is a receive beam to receive the downlink referencesignal. Similarly, an “uplink” beam may be either a transmit beam or areceive beam, depending on the entity forming it. For example, if a basestation is forming the uplink beam, it is an uplink receive beam, and ifa UE is forming the uplink beam, it is an uplink transmit beam.

In 5G, the frequency spectrum in which wireless nodes (e.g., basestations 102/180, UEs 104/182) operate is divided into multiplefrequency ranges, FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In amulti-carrier system, such as 5G, one of the carrier frequencies isreferred to as the “primary carrier” or “anchor carrier” or “primaryserving cell” or “PCell,” and the remaining carrier frequencies arereferred to as “secondary carriers” or “secondary serving cells” or“SCells.” In carrier aggregation, the anchor carrier is the carrieroperating on the primary frequency (e.g., FR1) utilized by a UE 104/182and the cell in which the UE 104/182 either performs the initial radioresource control (RRC) connection establishment procedure or initiatesthe RRC connection re-establishment procedure. The primary carriercarries all common and UE-specific control channels, and may be acarrier in a licensed frequency (however, this is not always the case).A secondary carrier is a carrier operating on a second frequency (e.g.,FR2) that may be configured once the RRC connection is establishedbetween the UE 104 and the anchor carrier and that may be used toprovide additional radio resources. In some cases, the secondary carriermay be a carrier in an unlicensed frequency. The secondary carrier maycontain only necessary signaling information and signals, for example,those that are UE-specific may not be present in the secondary carrier,since both primary uplink and downlink carriers are typicallyUE-specific. This means that different UEs 104/182 in a cell may havedifferent downlink primary carriers. The same is true for the uplinkprimary carriers. The network is able to change the primary carrier ofany UE 104/182 at any time. This is done, for example, to balance theload on different carriers. Because a “serving cell” (whether a PCell oran SCell) corresponds to a carrier frequency/component carrier overwhich some base station is communicating, the term “cell,” “servingcell,” “component carrier,” “carrier frequency,” and the like can beused interchangeably.

For example, still referring to FIG. 1, one of the frequencies utilizedby the macro cell base stations 102 may be an anchor carrier (or“PCell”) and other frequencies utilized by the macro cell base stations102 and/or the mmW base station 180 may be secondary carriers(“SCells”). The simultaneous transmission and/or reception of multiplecarriers enables the UE 104/182 to significantly increase its datatransmission and/or reception rates. For example, two 20 MHz aggregatedcarriers in a multi-carrier system would theoretically lead to atwo-fold increase in data rate (i.e., 40 MHz), compared to that attainedby a single 20 MHz carrier.

The wireless communications system 100 may further include one or moreUEs, such as UE 190, that connects indirectly to one or morecommunication networks via one or more device-to-device (D2D)peer-to-peer (P2P) links. In the example of FIG. 1, UE 190 has a D2D P2Plink 192 with one of the UEs 104 connected to one of the base stations102 (e.g., through which UE 190 may indirectly obtain cellularconnectivity) and a D2D P2P link 194 with WLAN STA 152 connected to theWLAN AP 150 (through which UE 190 may indirectly obtain WLAN-basedInternet connectivity). In an example, the D2D P2P links 192 and 194 maybe supported with any well-known D2D RAT, such as LTE Direct (LTE-D),WiFi Direct (WiFi-D), Bluetooth®, and so on.

The wireless communications system 100 may further include a UE 164 thatmay communicate with a macro cell base station 102 over a communicationlink 120 and/or the mmW base station 180 over a mmW communication link184. For example, the macro cell base station 102 may support a PCelland one or more SCells for the UE 164 and the mmW base station 180 maysupport one or more SCells for the UE 164.

According to various aspects, FIG. 2A illustrates an example wirelessnetwork structure 200. For example, an NGC 210 (also referred to as a“5GC”) can be viewed functionally as control plane functions 214 (e.g.,UE registration, authentication, network access, gateway selection,etc.) and user plane functions 212, (e.g., UE gateway function, accessto data networks, IP routing, etc.) which operate cooperatively to formthe core network. User plane interface (NG-U) 213 and control planeinterface (NG-C) 215 connect the gNB 222 to the NGC 210 and specificallyto the control plane functions 214 and user plane functions 212. In anadditional configuration, an eNB 224 may also be connected to the NGC210 via NG-C 215 to the control plane functions 214 and NG-U 213 to userplane functions 212. Further, eNB 224 may directly communicate with gNB222 via a backhaul connection 223. In some configurations, the New RAN220 may only have one or more gNBs 222, while other configurationsinclude one or more of both eNBs 224 and gNBs 222. Either gNB 222 or eNB224 may communicate with UEs 204 (e.g., any of the UEs depicted in FIG.1). Another optional aspect may include location server 230, which maybe in communication with the NGC 210 to provide location assistance forUEs 204. The location server 230 can be implemented as a plurality ofseparate servers (e.g., physically separate servers, different softwaremodules on a single server, different software modules spread acrossmultiple physical servers, etc.), or alternately may each correspond toa single server. The location server 230 can be configured to supportone or more location services for UEs 204 that can connect to thelocation server 230 via the core network, NGC 210, and/or via theInternet (not illustrated). Further, the location server 230 may beintegrated into a component of the core network, or alternatively may beexternal to the core network.

According to various aspects, FIG. 2B illustrates another examplewireless network structure 250. For example, an NGC 260 (also referredto as a “5GC”) can be viewed functionally as control plane functions,provided by an access and mobility management function (AMF)/user planefunction (UPF) 264, and user plane functions, provided by a sessionmanagement function (SMF) 262, which operate cooperatively to form thecore network (i.e., NGC 260). User plane interface 263 and control planeinterface 265 connect the eNB 224 to the NGC 260 and specifically to SMF262 and AMF/UPF 264, respectively. In an additional configuration, a gNB222 may also be connected to the NGC 260 via control plane interface 265to AMF/UPF 264 and user plane interface 263 to SMF 262. Further, eNB 224may directly communicate with gNB 222 via the backhaul connection 223,with or without gNB direct connectivity to the NGC 260. In someconfigurations, the New RAN 220 may only have one or more gNBs 222,while other configurations include one or more of both eNBs 224 and gNBs222. Either gNB 222 or eNB 224 may communicate with UEs 204 (e.g., anyof the UEs depicted in FIG. 1). The base stations of the New RAN 220communicate with the AMF-side of the AMF/UPF 264 over the N2 interfaceand the UPF-side of the AMF/UPF 264 over the N3 interface.

The functions of the AMF include registration management, connectionmanagement, reachability management, mobility management, lawfulinterception, transport for session management (SM) messages between theUE 204 and the SMF 262, transparent proxy services for routing SMmessages, access authentication and access authorization, transport forshort message service (SMS) messages between the UE 204 and the shortmessage service function (SMSF) (not shown), and security anchorfunctionality (SEAF). The AMF also interacts with the authenticationserver function (AUSF) (not shown) and the UE 204, and receives theintermediate key that was established as a result of the UE 204authentication process. In the case of authentication based on a UMTS(universal mobile telecommunications system) subscriber identity module(USIM), the AMF retrieves the security material from the AUSF. Thefunctions of the AMF also include security context management (SCM). TheSCM receives a key from the SEAF that it uses to derive access-networkspecific keys. The functionality of the AMF also includes locationservices management for regulatory services, transport for locationservices messages between the UE 204 and the location managementfunction (LMF) 270, as well as between the New RAN 220 and the LMF 270,evolved packet system (EPS) bearer identifier allocation forinterworking with the EPS, and UE 204 mobility event notification. Inaddition, the AMF also supports functionalities for non-3GPP accessnetworks.

Functions of the UPF include acting as an anchor point forintra-/inter-RAT mobility (when applicable), acting as an externalprotocol data unit (PDU) session point of interconnect to the datanetwork (not shown), providing packet routing and forwarding, packetinspection, user plane policy rule enforcement (e.g., gating,redirection, traffic steering), lawful interception (user planecollection), traffic usage reporting, quality of service (QoS) handlingfor the user plane (e.g., UL/DL rate enforcement, reflective QoS markingin the DL), UL traffic verification (service data flow (SDF) to QoS flowmapping), transport level packet marking in the UL and DL, DL packetbuffering and DL data notification triggering, and sending andforwarding of one or more “end markers” to the source RAN node.

The functions of the SMF 262 include session management, UE Internetprotocol (IP) address allocation and management, selection and controlof user plane functions, configuration of traffic steering at the UPF toroute traffic to the proper destination, control of part of policyenforcement and QoS, and downlink data notification. The interface overwhich the SMF 262 communicates with the AMF-side of the AMF/UPF 264 isreferred to as the N11 interface.

Another optional aspect may include a LMF 270, which may be incommunication with the NGC 260 to provide location assistance for UEs204. The LMF 270 can be implemented as a plurality of separate servers(e.g., physically separate servers, different software modules on asingle server, different software modules spread across multiplephysical servers, etc.), or alternately may each correspond to a singleserver. The LMF 270 can be configured to support one or more locationservices for UEs 204 that can connect to the LMF 270 via the corenetwork, NGC 260, and/or via the Internet (not illustrated).

FIGS. 3A, 3B, and 3C illustrate several sample components (representedby corresponding blocks) that may be incorporated into a UE 302 (whichmay correspond to any of the UEs described herein), a base station 304(which may correspond to any of the base stations described herein), anda network entity 306 (which may correspond to or embody any of thenetwork functions described herein, including the location server 230and the LMF 270) to support the file transmission operations as taughtherein. It will be appreciated that these components may be implementedin different types of apparatuses in different implementations (e.g., inan ASIC, in a system-on-chip (SoC), etc.). The illustrated componentsmay also be incorporated into other apparatuses in a communicationsystem. For example, other apparatuses in a system may includecomponents similar to those described to provide similar functionality.Also, a given apparatus may contain one or more of the components. Forexample, an apparatus may include multiple transceiver components thatenable the apparatus to operate on multiple carriers and/or communicatevia different technologies.

The UE 302 and the base station 304 each include wireless wide areanetwork (WWAN) transceiver 310 and 350, respectively, configured tocommunicate via one or more wireless communication networks (not shown),such as an NR network, an LTE network, a GSM network, and/or the like.The WWAN transceivers 310 and 350 may be connected to one or moreantennas 316 and 356, respectively, for communicating with other networknodes, such as other UEs, access points, base stations (e.g., eNBs,gNBs), etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc.)over a wireless communication medium of interest (e.g., some set oftime/frequency resources in a particular frequency spectrum). The WWANtransceivers 310 and 350 may be variously configured for transmittingand encoding signals 318 and 358 (e.g., messages, indications,information, and so on), respectively, and, conversely, for receivingand decoding signals 318 and 358 (e.g., messages, indications,information, pilots, and so on), respectively, in accordance with thedesignated RAT. Specifically, the transceivers 310 and 350 include oneor more transmitters 314 and 354, respectively, for transmitting andencoding signals 318 and 358, respectively, and one or more receivers312 and 352, respectively, for receiving and decoding signals 318 and358, respectively.

The UE 302 and the base station 304 also include, at least in somecases, wireless local area network (WLAN) transceivers 320 and 360,respectively. The WLAN transceivers 320 and 360 may be connected to oneor more antennas 326 and 366, respectively, for communicating with othernetwork nodes, such as other UEs, access points, base stations, etc.,via at least one designated RAT (e.g., WiFi, LTE-D, Bluetooth®, etc.)over a wireless communication medium of interest. The WLAN transceivers320 and 360 may be variously configured for transmitting and encodingsignals 328 and 368 (e.g., messages, indications, information, and soon), respectively, and, conversely, for receiving and decoding signals328 and 368 (e.g., messages, indications, information, pilots, and soon), respectively, in accordance with the designated RAT. Specifically,the transceivers 320 and 360 include one or more transmitters 324 and364, respectively, for transmitting and encoding signals 328 and 368,respectively, and one or more receivers 322 and 362, respectively, forreceiving and decoding signals 328 and 368, respectively.

Transceiver circuitry including a transmitter and a receiver maycomprise an integrated device (e.g., embodied as a transmitter circuitand a receiver circuit of a single communication device) in someimplementations, may comprise a separate transmitter device and aseparate receiver device in some implementations, or may be embodied inother ways in other implementations. In an aspect, a transmitter mayinclude or be coupled to a plurality of antennas (e.g., antennas 316,336, and 376), such as an antenna array, that permits the respectiveapparatus to perform transmit “beamforming,” as described herein.Similarly, a receiver may include or be coupled to a plurality ofantennas (e.g., antennas 316, 336, and 376), such as an antenna array,that permits the respective apparatus to perform receive beamforming, asdescribed herein. In an aspect, the transmitter and receiver may sharethe same plurality of antennas (e.g., antennas 316, 336, and 376), suchthat the respective apparatus can only receive or transmit at a giventime, not both at the same time. A wireless communication device (e.g.,one or both of the transceivers 310 and 320 and/or 350 and 360) of theapparatuses 302 and/or 304 may also comprise a network listen module(NLM) or the like for performing various measurements.

The apparatuses 302 and 304 also include, at least in some cases,satellite positioning systems (SPS) receivers 330 and 370. The SPSreceivers 330 and 370 may be connected to one or more antennas 336 and376, respectively, for receiving SPS signals 338 and 378, respectively,such as global positioning system (GPS) signals, global navigationsatellite system (GLONASS) signals, Galileo signals, Beidou signals,Indian Regional Navigation Satellite System (NAVIC), Quasi-ZenithSatellite System (QZSS), etc. The SPS receivers 330 and 370 may compriseany suitable hardware and/or software for receiving and processing SPSsignals 338 and 378, respectively. The SPS receivers 330 and 370 requestinformation and operations as appropriate from the other systems, andperforms calculations necessary to determine the apparatus' 302 and 304positions using measurements obtained by any suitable SPS algorithm.

The base station 304 and the network entity 306 each include at leastone network interfaces 380 and 390 for communicating with other networkentities. For example, the network interfaces 380 and 390 (e.g., one ormore network access ports) may be configured to communicate with one ormore network entities via a wire-based or wireless backhaul connection.In some aspects, the network interfaces 380 and 390 may be implementedas transceivers configured to support wire-based or wireless signalcommunication. This communication may involve, for example, sending andreceiving: messages, parameters, or other types of information.

The apparatuses 302, 304, and 306 also include other components that maybe used in conjunction with the operations as disclosed herein. The UE302 includes processor circuitry implementing a processing system 332for providing functionality relating to, for example, false base station(FBS) detection as disclosed herein and for providing other processingfunctionality. The base station 304 includes a processing system 384 forproviding functionality relating to, for example, FBS detection asdisclosed herein and for providing other processing functionality. Thenetwork entity 306 includes a processing system 394 for providingfunctionality relating to, for example, FBS detection as disclosedherein and for providing other processing functionality. In an aspect,the processing systems 332, 384, and 394 may include, for example, oneor more general purpose processors, multi-core processors, ASICs,digital signal processors (DSPs), field programmable gate arrays (FPGA),or other programmable logic devices or processing circuitry.

The apparatuses 302, 304, and 306 include memory circuitry implementingmemory components 340, 386, and 396 (e.g., each including a memorydevice), respectively, for maintaining information (e.g., informationindicative of reserved resources, thresholds, parameters, and so on). Insome cases, the apparatuses 302, 304, and 306 may include positioningmeasurement modules 342, 388 and 389, respectively. The positioningmeasurement modules 342, 388 and 389 may be hardware circuits that arepart of or coupled to the processing systems 332, 384, and 394,respectively, that, when executed, cause the apparatuses 302, 304, and306 to perform the functionality described herein. Alternatively, thepositioning measurement modules 342, 388 and 389 may be memory modules(as shown in FIGS. 3A-C) stored in the memory components 340, 386, and396, respectively, that, when executed by the processing systems 332,384, and 394, cause the apparatuses 302, 304, and 306 to perform thefunctionality described herein.

The UE 302 may include one or more sensors 344 coupled to the processingsystem 332 to provide movement and/or orientation information that isindependent of motion data derived from signals received by the WWANtransceiver 310, the WLAN transceiver 320, and/or the GPS receiver 330.By way of example, the sensor(s) 344 may include an accelerometer (e.g.,a micro-electrical mechanical systems (MEMS) device), a gyroscope, ageomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometricpressure altimeter), and/or any other type of movement detection sensor.Moreover, the sensor(s) 344 may include a plurality of different typesof devices and combine their outputs in order to provide motioninformation. For example, the sensor(s) 344 may use a combination of amulti-axis accelerometer and orientation sensors to provide the abilityto compute positions in 2D and/or 3D coordinate systems.

In addition, the UE 302 includes a user interface 346 for providingindications (e.g., audible and/or visual indications) to a user and/orfor receiving user input (e.g., upon user actuation of a sensing devicesuch a keypad, a touch screen, a microphone, and so on). Although notshown, the apparatuses 304 and 306 may also include user interfaces.

Referring to the processing system 384 in more detail, in the downlink,IP packets from the network entity 306 may be provided to the processingsystem 384. The processing system 384 may implement functionality for anRRC layer, a packet data convergence protocol (PDCP) layer, a radio linkcontrol (RLC) layer, and a medium access control (MAC) layer. Theprocessing system 384 may provide RRC layer functionality associatedwith broadcasting of system information (e.g., master information block(MIB), system information blocks (SIBs)), RRC connection control (e.g.,RRC connection paging, RRC connection establishment, RRC connectionmodification, and RRC connection release), inter-RAT mobility, andmeasurement configuration for UE measurement reporting; PDCP layerfunctionality associated with header compression/decompression, security(ciphering, deciphering, integrity protection, integrity verification),and handover support functions; RLC layer functionality associated withthe transfer of upper layer packet data units (PDUs), error correctionthrough ARQ, concatenation, segmentation, and reassembly of RLC servicedata units (SDUs), re-segmentation of RLC data PDUs, and reordering ofRLC data PDUs; and MAC layer functionality associated with mappingbetween logical channels and transport channels, scheduling informationreporting, error correction, priority handling, and logical channelprioritization.

The transmitter 354 and the receiver 352 may implement Layer-1functionality associated with various signal processing functions.Layer-1, which includes a physical (PHY) layer, may include errordetection on the transport channels, forward error correction (FEC)coding/decoding of the transport channels, interleaving, rate matching,mapping onto physical channels, modulation/demodulation of physicalchannels, and MIMO antenna processing. The transmitter 354 handlesmapping to signal constellations based on various modulation schemes(e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying(QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an orthogonalfrequency division multiplexing (OFDM) subcarrier, multiplexed with areference signal (e.g., pilot) in the time and/or frequency domain, andthen combined together using an Inverse Fast Fourier Transform (IFFT) toproduce a physical channel carrying a time domain OFDM symbol stream.The OFDM stream is spatially precoded to produce multiple spatialstreams. Channel estimates from a channel estimator may be used todetermine the coding and modulation scheme, as well as for spatialprocessing. The channel estimate may be derived from a reference signaland/or channel condition feedback transmitted by the UE 302. Eachspatial stream may then be provided to one or more different antennas356. The transmitter 354 may modulate an RF carrier with a respectivespatial stream for transmission.

At the UE 302, the receiver 312 receives a signal through its respectiveantenna(s) 316. The receiver 312 recovers information modulated onto anRF carrier and provides the information to the processing system 332.The transmitter 314 and the receiver 312 implement Layer-1 functionalityassociated with various signal processing functions. The receiver 312may perform spatial processing on the information to recover any spatialstreams destined for the UE 302. If multiple spatial streams aredestined for the UE 302, they may be combined by the receiver 312 into asingle OFDM symbol stream. The receiver 312 then converts the OFDMsymbol stream from the time-domain to the frequency domain using a fastFourier transform (FFT). The frequency domain signal comprises aseparate OFDM symbol stream for each subcarrier of the OFDM signal. Thesymbols on each subcarrier, and the reference signal, are recovered anddemodulated by determining the most likely signal constellation pointstransmitted by the base station 304. These soft decisions may be basedon channel estimates computed by a channel estimator. The soft decisionsare then decoded and de-interleaved to recover the data and controlsignals that were originally transmitted by the base station 304 on thephysical channel. The data and control signals are then provided to theprocessing system 332, which implements Layer-3 and Layer-2functionality.

In the UL, the processing system 332 provides demultiplexing betweentransport and logical channels, packet reassembly, deciphering, headerdecompression, and control signal processing to recover IP packets fromthe core network. The processing system 332 is also responsible forerror detection.

Similar to the functionality described in connection with the DLtransmission by the base station 304, the processing system 332 providesRRC layer functionality associated with system information (e.g., MIB,SIBs) acquisition, RRC connections, and measurement reporting; PDCPlayer functionality associated with header compression/decompression,and security (ciphering, deciphering, integrity protection, integrityverification); RLC layer functionality associated with the transfer ofupper layer PDUs, error correction through ARQ, concatenation,segmentation, and reassembly of RLC SDUs, re-segmentation of RLC dataPDUs, and reordering of RLC data PDUs; and MAC layer functionalityassociated with mapping between logical channels and transport channels,multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing ofMAC SDUs from TBs, scheduling information reporting, error correctionthrough HARQ, priority handling, and logical channel prioritization.

Channel estimates derived by the channel estimator from a referencesignal or feedback transmitted by the base station 304 may be used bythe transmitter 314 to select the appropriate coding and modulationschemes, and to facilitate spatial processing. The spatial streamsgenerated by the transmitter 314 may be provided to different antenna(s)316. The transmitter 314 may modulate an RF carrier with a respectivespatial stream for transmission.

The UL transmission is processed at the base station 304 in a mannersimilar to that described in connection with the receiver function atthe UE 302. The receiver 352 receives a signal through its respectiveantenna(s) 356. The receiver 352 recovers information modulated onto anRF carrier and provides the information to the processing system 384.

In the UL, the processing system 384 provides demultiplexing betweentransport and logical channels, packet reassembly, deciphering, headerdecompression, control signal processing to recover IP packets from theUE 302. IP packets from the processing system 384 may be provided to thecore network. The processing system 384 is also responsible for errordetection.

For convenience, the apparatuses 302, 304, and/or 306 are shown in FIGS.3A-C as including various components that may be configured according tothe various examples described herein. It will be appreciated, however,that the illustrated blocks may have different functionality indifferent designs.

The various components of the apparatuses 302, 304, and 306 maycommunicate with each other over data buses 334, 382, and 392,respectively. The components of FIGS. 3A-C may be implemented in variousways. In some implementations, the components of FIGS. 3A-C may beimplemented in one or more circuits such as, for example, one or moreprocessors and/or one or more ASICs (which may include one or moreprocessors). Here, each circuit may use and/or incorporate at least onememory component for storing information or executable code used by thecircuit to provide this functionality. For example, some or all of thefunctionality represented by blocks 310 to 346 may be implemented byprocessor and memory component(s) of the UE 302 (e.g., by execution ofappropriate code and/or by appropriate configuration of processorcomponents). Similarly, some or all of the functionality represented byblocks 350 to 388 may be implemented by processor and memorycomponent(s) of the base station 304 (e.g., by execution of appropriatecode and/or by appropriate configuration of processor components). Also,some or all of the functionality represented by blocks 390 to 396 may beimplemented by processor and memory component(s) of the network entity306 (e.g., by execution of appropriate code and/or by appropriateconfiguration of processor components). For simplicity, variousoperations, acts, and/or functions are described herein as beingperformed “by a UE,” “by a base station,” “by a positioning entity,”etc. However, as will be appreciated, such operations, acts, and/orfunctions may actually be performed by specific components orcombinations of components of the UE, base station, positioning entity,etc., such as the processing systems 332, 384, 394, the transceivers310, 320, 350, and 360, the memory components 340, 386, and 396, thepositioning measurement modules 342, 388 and 389, etc.

FIG. 4A is a diagram 400 illustrating an example of a DL framestructure, according to aspects of the disclosure. FIG. 4B is a diagram430 illustrating an example of channels within the DL frame structure,according to aspects of the disclosure. Other wireless communicationstechnologies may have a different frame structures and/or differentchannels.

LTE, and in some cases NR, utilizes OFDM on the downlink andsingle-carrier frequency division multiplexing (SC-FDM) on the uplink.Unlike LTE, however, NR has an option to use OFDM on the uplink as well.OFDM and SC-FDM partition the system bandwidth into multiple (K)orthogonal subcarriers, which are also commonly referred to as tones,bins, etc. Each subcarrier may be modulated with data. In general,modulation symbols are sent in the frequency domain with OFDM and in thetime domain with SC-FDM. The spacing between adjacent subcarriers may befixed, and the total number of subcarriers (K) may be dependent on thesystem bandwidth. For example, the spacing of the subcarriers may be 15kHz and the minimum resource allocation (resource block) may be 12subcarriers (or 180 kHz). Consequently, the nominal FFT size may beequal to 128, 256, 512, 1024, or 2048 for system bandwidth of 1.25, 2.5,5, 10, or 20 megahertz (MHz), respectively. The system bandwidth mayalso be partitioned into subbands. For example, a subband may cover 1.08MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16subbands for system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz,respectively.

LTE supports a single numerology (subcarrier spacing, symbol length,etc.). In contrast NR may support multiple numerologies, for example,subcarrier spacing of 15 kHz, 30 kHz, 60 kHz, 120 kHz and 204 kHz orgreater may be available. Table 1 provided below lists some variousparameters for different NR numerologies.

TABLE 1 Max. nominal Subcarrier Symbol system BW spacing Symbols/ slots/slots/ slot duration (MHz) with (kHz) slot subframe frame (ms) (μs) 4KFFT size 15 14 1 10 1 66.7 50 30 14 2 20 0.5 33.3 100 60 14 4 40 0.2516.7 100 120 14 8 80 0.125 8.33 400 240 14 16 160 0.0625 4.17 800

In the examples of FIGS. 4A and 4B, a numerology of 15 kHz is used.Thus, in the time domain, a frame (e.g., 10 ms) is divided into 10equally sized subframes of 1 ms each, and each subframe includes onetime slot. In FIGS. 4A and 4B, time is represented horizontally (e.g.,on the X axis) with time increasing from left to right, while frequencyis represented vertically (e.g., on the Y axis) with frequencyincreasing (or decreasing) from bottom to top.

A resource grid may be used to represent time slots, each time slotincluding one or more time concurrent resource blocks (RBs) (alsoreferred to as physical RBs (PRBs)) in the frequency domain. Theresource grid is further divided into multiple resource elements (REs).An RE may correspond to one symbol length in the time domain and onesubcarrier in the frequency domain. In the numerology of FIGS. 4A and4B, for a normal cyclic prefix, an RB may contain 12 consecutivesubcarriers in the frequency domain and 7 consecutive symbols (for DL,OFDM symbols; for UL, SC-FDMA symbols) in the time domain, for a totalof 84 REs. For an extended cyclic prefix, an RB may contain 12consecutive subcarriers in the frequency domain and 6 consecutivesymbols in the time domain, for a total of 72 REs. The number of bitscarried by each RE depends on the modulation scheme.

As illustrated in FIG. 4A, some of the REs carry DL reference (pilot)signals (DL-RS) for channel estimation at the UE. The DL-RS may includedemodulation reference signals (DMRS) and channel state informationreference signals (CSI-RS), exemplary locations of which are labeled “R”in FIG. 4A.

FIG. 4B illustrates an example of various channels within a DL subframeof a frame. The physical downlink control channel (PDCCH) carries DLcontrol information (DCI) within one or more control channel elements(CCEs), each CCE including nine RE groups (REGs), each REG includingfour consecutive REs in an OFDM symbol. The DCI carries informationabout UL resource allocation (persistent and non-persistent) anddescriptions about DL data transmitted to the UE. Multiple (e.g., up to8) DCIs can be configured in the PDCCH, and these DCIs can have one ofmultiple formats. For example, there are different DCI formats for ULscheduling, for non-MIMO DL scheduling, for MIMO DL scheduling, and forUL power control.

A primary synchronization signal (PSS) is used by a UE to determinesubframe/symbol timing and a physical layer identity. A secondarysynchronization signal (SSS) is used by a UE to determine a physicallayer cell identity group number and radio frame timing. Based on thephysical layer identity and the physical layer cell identity groupnumber, the UE can determine a PCI. Based on the PCI, the UE candetermine the locations of the aforementioned DL-RS. The physicalbroadcast channel (PBCH), which carries an MIB, may be logically groupedwith the PSS and SSS to form an SSB (also referred to as an SS/PBCH).The MIB provides a number of RBs in the DL system bandwidth and a systemframe number (SFN). The physical downlink shared channel (PDSCH) carriesuser data, broadcast system information not transmitted through the PBCHsuch as system information blocks (SIBs), and paging messages.

In some cases, the DL RS illustrated in FIG. 4A may be positioningreference signals (PRS). FIG. 5 illustrates an exemplary PRSconfiguration 500 for a cell supported by a wireless node (such as abase station 102). FIG. 5 shows how PRS positioning occasions aredetermined by a system frame number (SFN), a cell specific subframeoffset (APRs) 552, and the PRS periodicity (T_(PRS)) 520. Typically, thecell specific PRS subframe configuration is defined by a “PRSConfiguration Index” I_(PRS) included in observed time difference ofarrival (OTDOA) assistance data. The PRS periodicity (T_(PRS)) 520 andthe cell specific subframe offset (APRS) are defined based on the PRSconfiguration index I_(PRS), as illustrated in Table 2 below.

TABLE 2 PRS configuration PRS periodicity PRS subframe offset IndexI_(PRS) T_(PRS) (subframes) Δ_(PRS) (subframes)  0-159 160 I_(PRS)160-479 320 I_(PRS) − 160   480-1119 640 I_(PRS) − 480  1120-2399 1280I_(PRS) − 1120 2400-2404 5 I_(PRS) − 2400 2405-2414 10 I_(PRS) − 24052415-2434 20 I_(PRS) − 2415 2435-2474 40 I_(PRS) − 2435 2475-2554 80I_(PRS) − 2475 2555-4095 Reserved

A PRS configuration is defined with reference to the SFN of a cell thattransmits PRS. PRS instances, for the first subframe of the NPRSdownlink subframes comprising a first PRS positioning occasion, maysatisfy:

(10×f+└n _(s)/2┘−Δ_(PRS))mod T _(PRS)=0,

where n_(f) is the SFN with 0≤n_(f)≤1023, n_(s) is the slot numberwithin the radio frame defined by n_(f) with 0≤n_(s)≤19, T_(PRS) is thePRS periodicity 520, and Δ_(PRS) is the cell-specific subframe offset552.

As shown in FIG. 5, the cell specific subframe offset Δ_(PRS) 552 may bedefined in terms of the number of subframes transmitted starting fromsystem frame number 0 (Slot ‘Number 0’, marked as slot 550) to the startof the first (subsequent) PRS positioning occasion. In the example inFIG. 5, the number of consecutive positioning subframes (NPRs) in eachof the consecutive PRS positioning occasions 518 a, 518 b, and 518 cequals 4. That is, each shaded block representing PRS positioningoccasions 518 a, 518 b, and 518 c represents four subframes.

In some aspects, when a UE receives a PRS configuration index I_(PRS) inthe OTDOA assistance data for a particular cell, the UE may determinethe PRS periodicity T_(PRS) 520 and PRS subframe offset Δ_(PRS) usingTable 2. The UE may then determine the radio frame, subframe, and slotwhen a PRS is scheduled in the cell (e.g., using equation (1)). TheOTDOA assistance data may be determined by, for example, the locationserver (e.g., location server 230, LMF 270), and includes assistancedata for a reference cell, and a number of neighbor cells supported byvarious base stations.

Typically, PRS occasions from all cells in a network that use the samefrequency are aligned in time and may have a fixed known time offset(e.g., cell-specific subframe offset 552) relative to other cells in thenetwork that use a different frequency. In SFN-synchronous networks, allwireless nodes (e.g., base stations 102) may be aligned on both frameboundary and system frame number. Therefore, in SFN-synchronousnetworks, all cells supported by the various wireless nodes may use thesame PRS configuration index for any particular frequency of PRStransmission. On the other hand, in SFN-asynchronous networks, thevarious wireless nodes may be aligned on a frame boundary, but notsystem frame number. Thus, in SFN-asynchronous networks the PRSconfiguration index for each cell may be configured separately by thenetwork so that PRS occasions align in time.

A UE may determine the timing of the PRS occasions of the reference andneighbor cells for OTDOA positioning, if the UE can obtain the celltiming (e.g., SFN) of at least one of the cells, e.g., the referencecell or a serving cell. The timing of the other cells may then bederived by the UE based, for example, on the assumption that PRSoccasions from different cells overlap.

A collection of resource elements that are used for transmission of PRSis referred to as a “PRS resource.” The collection of resource elementscan span multiple PRBs in the frequency domain and N (e.g., 1 or more)consecutive symbol(s) 460 within a slot 430 in the time domain. In agiven OFDM symbol 460, a PRS resource occupies consecutive PRBs. A PRSresource is described by at least the following parameters: PRS resourceidentifier (ID), sequence ID, comb size-N, resource element offset inthe frequency domain, starting slot and starting symbol, number ofsymbols per PRS resource (i.e., the duration of the PRS resource), andQCL information (e.g., QCL with other DL reference signals). In somedesigns, one antenna port is supported. The comb size indicates thenumber of subcarriers in each symbol carrying PRS. For example, acomb-size of comb-4 means that every fourth subcarrier of a given symbolcarries PRS.

A “PRS resource set” is a set of PRS resources used for the transmissionof PRS signals, where each PRS resource has a PRS resource ID. Inaddition, the PRS resources in a PRS resource set are associated withthe same transmission-reception point (TRP). A PRS resource ID in a PRSresource set is associated with a single beam transmitted from a singleTRP (where a TRP may transmit one or more beams). That is, each PRSresource of a PRS resource set may be transmitted on a different beam,and as such, a “PRS resource” can also be referred to as a “beam.” Notethat this does not have any implications on whether the TRPs and thebeams on which PRS are transmitted are known to the UE. A “PRS occasion”is one instance of a periodically repeated time window (e.g., a group ofone or more consecutive slots) where PRS are expected to be transmitted.A PRS occasion may also be referred to as a “PRS positioning occasion,”a “positioning occasion,” or simply an “occasion.”

Note that the terms “positioning reference signal” and “PRS” maysometimes refer to specific reference signals that are used forpositioning in LTE or NR systems. However, as used herein, unlessotherwise indicated, the terms “positioning reference signal” and “PRS”refer to any type of reference signal that can be used for positioning,such as but not limited to, PRS signals in LTE or NR, navigationreference signals (NRSs) in 5G, transmitter reference signals (TRSs),cell-specific reference signals (CRSs), channel state informationreference signals (CSI-RSs), primary synchronization signals (PSSs),secondary synchronization signals (SSSs), SSB, etc.

An SRS is an uplink-only signal that a UE transmits to help the basestation obtain the channel state information (CSI) for each user.Channel state information describes how an RF signal propagates from theUE to the base station and represents the combined effect of scattering,fading, and power decay with distance. The system uses the SRS forresource scheduling, link adaptation, massive MIMO, beam management,etc.

Several enhancements over the previous definition of SRS have beenproposed for SRS for positioning (SRS-P), such as a new staggeredpattern within an SRS resource, a new comb type for SRS, new sequencesfor SRS, a higher number of SRS resource sets per component carrier, anda higher number of SRS resources per component carrier. In addition, theparameters “SpatialRelationInfo” and “PathLossReference” are to beconfigured based on a DL RS from a neighboring TRP. Further still, oneSRS resource may be transmitted outside the active bandwidth part (BWP),and one SRS resource may span across multiple component carriers.Lastly, the UE may transmit through the same transmit beam from multipleSRS resources for UL-AoA. All of these are features that are additionalto the current SRS framework, which is configured through RRC higherlayer signaling (and potentially triggered or activated through MACcontrol element (CE) or downlink control information (DCI)).

As noted above, SRSs in NR are UE-specifically configured referencesignals transmitted by the UE used for the purposes of the sounding theuplink radio channel. Similar to CSI-RS, such sounding provides variouslevels of knowledge of the radio channel characteristics. On oneextreme, the SRS can be used at the gNB simply to obtain signal strengthmeasurements, e.g., for the purposes of UL beam management. On the otherextreme, SRS can be used at the gNB to obtain detailed amplitude andphase estimates as a function of frequency, time and space. In NR,channel sounding with SRS supports a more diverse set of use casescompared to LTE (e.g., downlink CSI acquisition for reciprocity-basedgNB transmit beamforming (downlink MIMO); uplink CSI acquisition forlink adaptation and codebook/non-codebook based precoding for uplinkMIMO, uplink beam management, etc.).

The SRS can be configured using various options. The time/frequencymapping of an SRS resource is defined by the following characteristics.

-   -   Time duration N_(symb) ^(SRS)—The time duration of an SRS        resource can be 1, 2, or 4 consecutive OFDM symbols within a        slot, in contrast to LTE which allows only a single OFDM symbol        per slot.    -   Starting symbol location l₀—The starting symbol of an SRS        resource can be located anywhere within the last 6 OFDM symbols        of a slot provided the resource does not cross the end-of-slot        boundary.    -   Repetition factor R—For an SRS resource configured with        frequency hopping, repetition allows the same set of subcarriers        to be sounded in R consecutive OFDM symbols before the next hop        occurs (as used herein, a “hop” refers to specifically to a        frequency hop). For example, values of R are 1, 2, 4 where        R≤N_(symb) ^(SRS).    -   Transmission comb spacing K_(TC) and comb offset k_(TC)—An SRS        resource may occupy resource elements (REs) of a frequency        domain comb structure, where the comb spacing is either 2 or 4        REs like in LTE. Such a structure allows frequency domain        multiplexing of different SRS resources of the same or different        users on different combs, where the different combs are offset        from each other by an integer number of REs. The comb offset is        defined with respect to a PRB boundary, and can take values in        the range 0, 1, . . . , K_(TC)−1 REs. Thus, for comb spacing        K_(TC)=2, there are 2 different combs available for multiplexing        if needed, and for comb spacing K_(TC)=4, there are 4 different        available combs.    -   Periodicity and slot offset for the case of        periodic/semi-persistent SRS.    -   Sounding bandwidth within a bandwidth part.

For low latency positioning, a gNB may trigger a UL SRS-P via a DCI(e.g., transmitted SRS-P may include repetition or beam-sweeping toenable several gNBs to receive the SRS-P). Alternatively, the gNB maysend information regarding aperiodic PRS transmission to the UE (e.g.,this configuration may include information about PRS from multiple gNBsto enable the UE to perform timing computations for positioning(UE-based) or for reporting (UE-assisted). While various embodiments ofthe present disclosure relate to DL PRS-based positioning procedures,some or all of such embodiments may also apply to UL SRS-P-basedpositioning procedures.

Note that the terms “sounding reference signal”, “SRS” and “SRS-P” maysometimes refer to specific reference signals that are used forpositioning in LTE or NR systems. However, as used herein, unlessotherwise indicated, the terms “sounding reference signal”, “SRS” and“SRS-P” refer to any type of reference signal that can be used forpositioning, such as but not limited to, SRS signals in LTE or NR,navigation reference signals (NRSs) in 5G, transmitter reference signals(TRSs), random access channel (RACH) signals for positioning (e.g., RACHpreambles, such as Msg-1 in 4-Step RACH procedure or Msg-A in 2-StepRACH procedure), etc.

3GPP Rel. 16 introduced various NR positioning aspects directed toincrease location accuracy of positioning schemes that involvemeasurement(s) associated with one or more UL or DL PRSs (e.g., higherbandwidth (BW), FR2 beam-sweeping, angle-based measurements such asAngle of Arrival (AoA) and Angle of Departure (AoD) measurements,multi-cell Round-Trip Time (RTT) measurements, etc.). If latencyreduction is a priority, then UE-based positioning techniques (e.g.,DL-only techniques without UL location measurement reporting) aretypically used. However, if latency is less of a concern, thenUE-assisted positioning techniques can be used, whereby UE-measured datais reported to a network entity (e.g., location server 230, LMF 270,etc.). Latency associated UE-assisted positioning techniques can bereduced somewhat by implementing the LMF in the RAN.

Layer-3 (L3) signaling (e.g., RRC or Location Positioning Protocol(LPP)) is typically used to transport reports that compriselocation-based data in association with UE-assisted positioningtechniques. L3 signaling is associated with relatively high latency(e.g., above 100 ms) compared with Layer-1 (L1, or PHY layer) signalingor Layer-2 (L2, or MAC layer) signaling. In some cases, lower latency(e.g., less than 100 ms, less than 10 ms, etc.) between the UE and theRAN for location-based reporting may be desired. In such cases, L3signaling may not be capable of reaching these lower latency levels. L3signaling of positioning measurements may comprise any combination ofthe following:

-   -   One or multiple TOA, TDOA, RSRP or Rx-Tx measurements,    -   One or multiple AoA/AoD (e.g., currently agreed only for        gNB->LMF reporting DL AoA and UL AoD) measurements,    -   One or multiple Multipath reporting measurements, e.g., per-path        ToA, RSRP, AoA/AoD (e.g., currently only per-path ToA allowed in        LTE)    -   One or multiple motion states (e.g., walking, driving, etc.) and        trajectories (e.g., currently for UE), and/or    -   One or multiple report quality indications.

More recently, L1 and L2 signaling has been contemplated for use inassociation with PRS-based reporting. For example, L1 and L2 signalingis currently used in some systems to transport CSI reports (e.g.,reporting of Channel Quality Indications (CQIs), Precoding MatrixIndicators (PMIs), Layer Indicators (Lis), L1-RSRP, etc.). CSI reportsmay comprise a set of fields in a pre-defined order (e.g., defined bythe relevant standard). A single UL transmission (e.g., on PUSCH orPUCCH) may include multiple reports, referred to herein as‘sub-reports’, which are arranged according to a pre-defined priority(e.g., defined by the relevant standard). In some designs, thepre-defined order may be based on an associated sub-report periodicity(e.g., aperiodic/semi-persistent/periodic (A/SP/P) over PUSCH/PUCCH),measurement type (e.g., L1-RSRP or not), serving cell index (e.g., incarrier aggregation (CA) case), and reportconfigID. With 2-part CSIreporting, the part 1s of all reports are grouped together, and the part2s are grouped separately, and each group is separately encoded (e.g.,part 1 payload size is fixed based on configuration parameters, whilepart 2 size is variable and depends on configuration parameters and alsoon associated part 1 content). A number of coded bits/symbols to beoutput after encoding and rate-matching is computed based on a number ofinput bits and beta factors, per the relevant standard. Linkages (e.g.,time offsets) are defined between instances of RSs being measured andcorresponding reporting. In some designs, CSI-like reporting ofPRS-based measurement data using L1 and L2 signaling may be implemented.

FIG. 6 illustrates an exemplary wireless communications system 600according to various aspects of the disclosure. In the example of FIG.6, a UE 604, which may correspond to any of the UEs described above withrespect to FIG. 1 (e.g., UEs 104, UE 182, UE 190, etc.), is attemptingto calculate an estimate of its position, or assist another entity(e.g., a base station or core network component, another UE, a locationserver, a third party application, etc.) to calculate an estimate of itsposition. The UE 604 may communicate wirelessly with a plurality of basestations 602 a-d (collectively, base stations 602), which may correspondto any combination of base stations 102 or 180 and/or WLAN AP 150 inFIG. 1, using RF signals and standardized protocols for the modulationof the RF signals and the exchange of information packets. By extractingdifferent types of information from the exchanged RF signals, andutilizing the layout of the wireless communications system 600 (i.e.,the base stations locations, geometry, etc.), the UE 604 may determineits position, or assist in the determination of its position, in apredefined reference coordinate system. In an aspect, the UE 604 mayspecify its position using a two-dimensional coordinate system; however,the aspects disclosed herein are not so limited, and may also beapplicable to determining positions using a three-dimensional coordinatesystem, if the extra dimension is desired. Additionally, while FIG. 6illustrates one UE 604 and four base stations 602, as will beappreciated, there may be more UEs 604 and more or fewer base stations602.

To support position estimates, the base stations 602 may be configuredto broadcast reference RF signals (e.g., Positioning Reference Signals(PRS), Cell-specific Reference Signals (CRS), Channel State InformationReference Signals (CSI-RS), synchronization signals, etc.) to UEs 604 intheir coverage areas to enable a UE 604 to measure reference RF signaltiming differences (e.g., OTDOA or RSTD) between pairs of network nodesand/or to identify the beam that best excite the LOS or shortest radiopath between the UE 604 and the transmitting base stations 602.Identifying the LOS/shortest path beam(s) is of interest not onlybecause these beams can subsequently be used for OTDOA measurementsbetween a pair of base stations 602, but also because identifying thesebeams can directly provide some positioning information based on thebeam direction. Moreover, these beams can subsequently be used for otherposition estimation methods that require precise ToA, such as round-triptime estimation based methods.

As used herein, a “network node” may be a base station 602, a cell of abase station 602, a remote radio head, an antenna of a base station 602,where the locations of the antennas of a base station 602 are distinctfrom the location of the base station 602 itself, or any other networkentity capable of transmitting reference signals. Further, as usedherein, a “node” may refer to either a network node or a UE.

A location server (e.g., location server 230) may send assistance datato the UE 604 that includes an identification of one or more neighborcells of base stations 602 and configuration information for referenceRF signals transmitted by each neighbor cell. Alternatively, theassistance data can originate directly from the base stations 602themselves (e.g., in periodically broadcasted overhead messages, etc.).Alternatively, the UE 604 can detect neighbor cells of base stations 602itself without the use of assistance data. The UE 604 (e.g., based inpart on the assistance data, if provided) can measure and (optionally)report the OTDOA from individual network nodes and/or RSTDs betweenreference RF signals received from pairs of network nodes. Using thesemeasurements and the known locations of the measured network nodes(i.e., the base station(s) 602 or antenna(s) that transmitted thereference RF signals that the UE 604 measured), the UE 604 or thelocation server can determine the distance between the UE 604 and themeasured network nodes and thereby calculate the location of the UE 604.

The term “position estimate” is used herein to refer to an estimate of aposition for a UE 604, which may be geographic (e.g., may comprise alatitude, longitude, and possibly altitude) or civic (e.g., may comprisea street address, building designation, or precise point or area withinor nearby to a building or street address, such as a particular entranceto a building, a particular room or suite in a building, or a landmarksuch as a town square). A position estimate may also be referred to as a“location,” a “position,” a “fix,” a “position fix,” a “location fix,” a“location estimate,” a “fix estimate,” or by some other term. The meansof obtaining a location estimate may be referred to generically as“positioning,” “locating,” or “position fixing.” A particular solutionfor obtaining a position estimate may be referred to as a “positionsolution.” A particular method for obtaining a position estimate as partof a position solution may be referred to as a “position method” or as a“positioning method.”

The term “base station” may refer to a single physical transmissionpoint or to multiple physical transmission points that may or may not beco-located. For example, where the term “base station” refers to asingle physical transmission point, the physical transmission point maybe an antenna of the base station (e.g., base station 602) correspondingto a cell of the base station. Where the term “base station” refers tomultiple co-located physical transmission points, the physicaltransmission points may be an array of antennas (e.g., as in a MIMOsystem or where the base station employs beamforming) of the basestation. Where the term “base station” refers to multiple non-co-locatedphysical transmission points, the physical transmission points may be aDistributed Antenna System (DAS) (a network of spatially separatedantennas connected to a common source via a transport medium) or aRemote Radio Head (RRH) (a remote base station connected to a servingbase station). Alternatively, the non-co-located physical transmissionpoints may be the serving base station receiving the measurement reportfrom the UE (e.g., UE 604) and a neighbor base station whose referenceRF signals the UE is measuring. Thus, FIG. 6 illustrates an aspect inwhich base stations 602 a and 602 b form a DAS/RRH 620. For example, thebase station 602 a may be the serving base station of the UE 604 and thebase station 602 b may be a neighbor base station of the UE 604. Assuch, the base station 602 b may be the RRH of the base station 602 a.The base stations 602 a and 602 b may communicate with each other over awired or wireless link 622.

To accurately determine the position of the UE 604 using the OTDOAsand/or RSTDs between RF signals received from pairs of network nodes,the UE 604 needs to measure the reference RF signals received over theLOS path (or the shortest NLOS path where an LOS path is not available),between the UE 604 and a network node (e.g., base station 602, antenna).However, RF signals travel not only by the LOS/shortest path between thetransmitter and receiver, but also over a number of other paths as theRF signals spread out from the transmitter and reflect off other objectssuch as hills, buildings, water, and the like on their way to thereceiver. Thus, FIG. 6 illustrates a number of LOS paths 610 and anumber of NLOS paths 612 between the base stations 602 and the UE 604.Specifically, FIG. 6 illustrates base station 602 a transmitting over anLOS path 610 a and an NLOS path 612 a, base station 602 b transmittingover an LOS path 610 b and two NLOS paths 612 b, base station 602 ctransmitting over an LOS path 610 c and an NLOS path 612 c, and basestation 602 d transmitting over two NLOS paths 612 d. As illustrated inFIG. 6, each NLOS path 612 reflects off some object 630 (e.g., abuilding). As will be appreciated, each LOS path 610 and NLOS path 612transmitted by a base station 602 may be transmitted by differentantennas of the base station 602 (e.g., as in a MIMO system), or may betransmitted by the same antenna of a base station 602 (therebyillustrating the propagation of an RF signal). Further, as used herein,the term “LOS path” refers to the shortest path between a transmitterand receiver, and may not be an actual LOS path, but rather, theshortest NLOS path.

In an aspect, one or more of base stations 602 may be configured to usebeamforming to transmit RF signals. In that case, some of the availablebeams may focus the transmitted RF signal along the LOS paths 610 (e.g.,the beams produce highest antenna gain along the LOS paths) while otheravailable beams may focus the transmitted RF signal along the NLOS paths612. A beam that has high gain along a certain path and thus focuses theRF signal along that path may still have some RF signal propagatingalong other paths; the strength of that RF signal naturally depends onthe beam gain along those other paths. An “RF signal” comprises anelectromagnetic wave that transports information through the spacebetween the transmitter and the receiver. As used herein, a transmittermay transmit a single “RF signal” or multiple “RF signals” to areceiver. However, as described further below, the receiver may receivemultiple “RF signals” corresponding to each transmitted RF signal due tothe propagation characteristics of RF signals through multipathchannels.

Where a base station 602 uses beamforming to transmit RF signals, thebeams of interest for data communication between the base station 602and the UE 604 will be the beams carrying RF signals that arrive at UE604 with the highest signal strength (as indicated by, e.g., theReceived Signal Received Power (RSRP) or SINR in the presence of adirectional interfering signal), whereas the beams of interest forposition estimation will be the beams carrying RF signals that excitethe shortest path or LOS path (e.g., an LOS path 610). In some frequencybands and for antenna systems typically used, these will be the samebeams. However, in other frequency bands, such as mmW, where typically alarge number of antenna elements can be used to create narrow transmitbeams, they may not be the same beams. As described below with referenceto FIG. 7, in some cases, the signal strength of RF signals on the LOSpath 610 may be weaker (e.g., due to obstructions) than the signalstrength of RF signals on an NLOS path 612, over which the RF signalsarrive later due to propagation delay.

FIG. 7 illustrates an exemplary wireless communications system 700according to various aspects of the disclosure. In the example of FIG.7, a UE 704, which may correspond to UE 604 in FIG. 6, is attempting tocalculate an estimate of its position, or to assist another entity(e.g., a base station or core network component, another UE, a locationserver, a third party application, etc.) to calculate an estimate of itsposition. The UE 704 may communicate wirelessly with a base station 702,which may correspond to one of base stations 602 in FIG. 6, using RFsignals and standardized protocols for the modulation of the RF signalsand the exchange of information packets.

As illustrated in FIG. 7, the base station 702 is utilizing beamformingto transmit a plurality of beams 711-715 of RF signals. Each beam711-715 may be formed and transmitted by an array of antennas of thebase station 702. Although FIG. 7 illustrates a base station 702transmitting five beams 711-715, as will be appreciated, there may bemore or fewer than five beams, beam shapes such as peak gain, width, andside-lobe gains may differ amongst the transmitted beams, and some ofthe beams may be transmitted by a different base station.

A beam index may be assigned to each of the plurality of beams 711-715for purposes of distinguishing RF signals associated with one beam fromRF signals associated with another beam. Moreover, the RF signalsassociated with a particular beam of the plurality of beams 711-715 maycarry a beam index indicator. A beam index may also be derived from thetime of transmission, e.g., frame, slot and/or OFDM symbol number, ofthe RF signal. The beam index indicator may be, for example, a three-bitfield for uniquely distinguishing up to eight beams. If two different RFsignals having different beam indices are received, this would indicatethat the RF signals were transmitted using different beams. If twodifferent RF signals share a common beam index, this would indicate thatthe different RF signals are transmitted using the same beam. Anotherway to describe that two RF signals are transmitted using the same beamis to say that the antenna port(s) used for the transmission of thefirst RF signal are spatially quasi-collocated with the antenna port(s)used for the transmission of the second RF signal.

In the example of FIG. 7, the UE 704 receives an NLOS data stream 723 ofRF signals transmitted on beam 713 and an LOS data stream 724 of RFsignals transmitted on beam 714. Although FIG. 7 illustrates the NLOSdata stream 723 and the LOS data stream 724 as single lines (dashed andsolid, respectively), as will be appreciated, the NLOS data stream 723and the LOS data stream 724 may each comprise multiple rays (i.e., a“cluster”) by the time they reach the UE 704 due, for example, to thepropagation characteristics of RF signals through multipath channels.For example, a cluster of RF signals is formed when an electromagneticwave is reflected off of multiple surfaces of an object, and reflectionsarrive at the receiver (e.g., UE 704) from roughly the same angle, eachtravelling a few wavelengths (e.g., centimeters) more or less thanothers. A “cluster” of received RF signals generally corresponds to asingle transmitted RF signal.

In the example of FIG. 7, the NLOS data stream 723 is not originallydirected at the UE 704, although, as will be appreciated, it could be,as are the RF signals on the NLOS paths 612 in FIG. 6. However, it isreflected off a reflector 740 (e.g., a building) and reaches the UE 704without obstruction, and therefore, may still be a relatively strong RFsignal. In contrast, the LOS data stream 724 is directed at the UE 704but passes through an obstruction 730 (e.g., vegetation, a building, ahill, a disruptive environment such as clouds or smoke, etc.), which maysignificantly degrade the RF signal. As will be appreciated, althoughthe LOS data stream 724 is weaker than the NLOS data stream 723, the LOSdata stream 724 will arrive at the UE 704 before the NLOS data stream723 because it follows a shorter path from the base station 702 to theUE 704.

As noted above, the beam of interest for data communication between abase station (e.g., base station 702) and a UE (e.g., UE 704) is thebeam carrying RF signals that arrives at the UE with the highest signalstrength (e.g., highest RSRP or SINR), whereas the beam of interest forposition estimation is the beam carrying RF signals that excite the LOSpath and that has the highest gain along the LOS path amongst all otherbeams (e.g., beam 714). That is, even if beam 713 (the NLOS beam) wereto weakly excite the LOS path (due to the propagation characteristics ofRF signals, even though not being focused along the LOS path), that weaksignal, if any, of the LOS path of beam 713 may not be as reliablydetectable (compared to that from beam 714), thus leading to greatererror in performing a positioning measurement.

While the beam of interest for data communication and the beam ofinterest for position estimation may be the same beams for somefrequency bands, for other frequency bands, such as mmW, they may not bethe same beams. As such, referring to FIG. 7, where the UE 704 isengaged in a data communication session with the base station 702 (e.g.,where the base station 702 is the serving base station for the UE 704)and not simply attempting to measure reference RF signals transmitted bythe base station 702, the beam of interest for the data communicationsession may be the beam 713, as it is carrying the unobstructed NLOSdata stream 723. The beam of interest for position estimation, however,would be the beam 714, as it carries the strongest LOS data stream 724,despite being obstructed.

FIG. 8A is a graph 800A showing the RF channel response at a receiver(e.g., UE 704) over time according to aspects of the disclosure. Underthe channel illustrated in FIG. 8A, the receiver receives a firstcluster of two RF signals on channel taps at time T1, a second clusterof five RF signals on channel taps at time T2, a third cluster of fiveRF signals on channel taps at time T3, and a fourth cluster of four RFsignals on channel taps at time T4. In the example of FIG. 8A, becausethe first cluster of RF signals at time T1 arrives first, it is presumedto be the LOS data stream (i.e., the data stream arriving over the LOSor the shortest path), and may correspond to the LOS data stream 724.The third cluster at time T3 is comprised of the strongest RF signals,and may correspond to the NLOS data stream 723. Seen from thetransmitter's side, each cluster of received RF signals may comprise theportion of an RF signal transmitted at a different angle, and thus eachcluster may be said to have a different angle of departure (AoD) fromthe transmitter. FIG. 8B is a diagram 800B illustrating this separationof clusters in AoD. The RF signal transmitted in AoD range 802 a maycorrespond to one cluster (e.g., “Cluster1”) in FIG. 8A, and the RFsignal transmitted in AoD range 802 b may correspond to a differentcluster (e.g., “Cluster3”) in FIG. 8A. Note that although AoD ranges ofthe two clusters depicted in FIG. 8B are spatially isolated, AoD rangesof some clusters may also partially overlap even though the clusters areseparated in time. For example, this may arise when two separatebuildings at same AoD from the transmitter reflect the signal towardsthe receiver. Note that although FIG. 8A illustrates clusters of two tofive channel taps (or “peaks”), as will be appreciated, the clusters mayhave more or fewer than the illustrated number of channel taps.

RAN1 NR may define UE measurements on DL reference signals (e.g., forserving, reference, and/or neighboring cells) applicable for NRpositioning, including DL reference signal time difference (RSTD)measurements for NR positioning, DL RSRP measurements for NRpositioning, and UE Rx-Tx (e.g., a hardware group delay from signalreception at UE receiver to response signal transmission at UEtransmitter, e.g., for time difference measurements for NR positioning,such as RTT).

RAN1 NR may define gNB measurements based on UL reference signalsapplicable for NR positioning, such as relative UL time of arrival(RTOA) for NR positioning, UL AoA measurements (e.g., including Azimuthand Zenith Angles) for NR positioning, UL RSRP measurements for NRpositioning, and gNB Rx-Tx (e.g., a hardware group delay from signalreception at gNB receiver to response signal transmission at gNBtransmitter, e.g., for time difference measurements for NR positioning,such as RTT).

FIG. 9 is a diagram 900 showing exemplary timings of RTT measurementsignals exchanged between a base station 902 (e.g., any of the basestations described herein) and a UE 904 (e.g., any of the UEs describedherein), according to aspects of the disclosure. In the example of FIG.9, the base station 902 sends an RTT measurement signal 910 (e.g., PRS,NRS, CRS, CSI-RS, etc.) to the UE 904 at time t₁. The RTT measurementsignal 910 has some propagation delay T_(Prop) as it travels from thebase station 902 to the UE 904. At time t₂ (the ToA of the RTTmeasurement signal 910 at the UE 904), the UE 904 receives/measures theRTT measurement signal 910. After some UE processing time, the UE 904transmits an RTT response signal 920 at time t₃. After the propagationdelay T_(Prop), the base station 902 receives/measures the RTT responsesignal 920 from the UE 904 at time t₄ (the ToA of the RTT responsesignal 920 at the base station 902).

In order to identify the ToA (e.g., t₂) of a reference signal (e.g., anRTT measurement signal 910) transmitted by a given network node (e.g.,base station 902), the receiver (e.g., UE 904) first jointly processesall the resource elements (REs) on the channel on which the transmitteris transmitting the reference signal, and performs an inverse Fouriertransform to convert the received reference signals to the time domain.The conversion of the received reference signals to the time domain isreferred to as estimation of the channel energy response (CER). The CERshows the peaks on the channel over time, and the earliest “significant”peak should therefore correspond to the ToA of the reference signal.Generally, the receiver will use a noise-related quality threshold tofilter out spurious local peaks, thereby presumably correctlyidentifying significant peaks on the channel. For example, the receivermay choose a ToA estimate that is the earliest local maximum of the CERthat is at least X dB higher than the median of the CER and a maximum YdB lower than the main peak on the channel. The receiver determines theCER for each reference signal from each transmitter in order todetermine the ToA of each reference signal from the differenttransmitters.

In some designs, the RTT response signal 920 may explicitly include thedifference between time t₃ and time t₂ (i.e., T_(Rx→Tx) 912). Using thismeasurement and the difference between time t₄ and time t₁ (i.e.,T_(Tx→Rx) 922), the base station 902 (or other positioning entity, suchas location server 230, LMF 270) can calculate the distance to the UE904 as:

$d = {{\frac{1}{2c}\left( {T_{{Tx}\rightarrow{Rx}} - T_{{Rx}\rightarrow{Tx}}} \right)} = {{\frac{1}{2c}\left( {t_{2} - t_{1}} \right)} - {\frac{1}{2c}\left( {t_{4} - t_{3}} \right)}}}$

where c is the speed of light. While not illustrated expressly in FIG.9, an additional source of delay or error may be due to UE and gNBhardware group delay for position location.

Various parameters associated with positioning can impact powerconsumption at the UE. Knowledge of such parameters can be used toestimate (or model) the UE power consumption. By accurately modeling thepower consumption of the UE, various power saving features and/orperformance enhancing features can be utilized in a predictive manner soas to improve the user experience.

In 3GPP Rel. 16, UE DL PRS processing capability is reported for maximumDL PRS bandwidth in MHz. In particular, the UE DL PRS processingcapability may comprise a duration of DL PRS symbols N in units of mswhich a UE can process every T ms assuming maximum DL PRS bandwidth inMHz, and a maximum number of DL PRS resources that the UE can process ina slot. The UE is not expected to process DL PRS without configurationof measurement gap in 3GPP Rel. 16. The UE DL PRS processing capabilityis defined for a single positioning frequency layer in 3GPP Rel. 16. TheUE capability for simultaneous DL PRS processing across positioningfrequency layers is not supported in 3GPP Rel. 16.

In 3GPP Rel. 17, UE power saving is a potential enhancement for NRpositioning. However, in currently contemplated designs, it is up toeach company on how to evaluate the power consumption for NRpositioning.

A “positioning frequency layer” is a collection of PRS Resource Setsacross one or more TRPs with certain shared parameters, e.g.:

-   -   the same SCS and CP type,    -   the same point-A,    -   the same value of DL PRS Bandwidth,    -   Granularity of 4 PRBs with a minimum of 24 PRBs and a maximum of        272 PRBs,    -   The same Start PRB (and center frequency), and/or    -   the same value of comb-Size.

In 3GPP Rel. 16, up to four positioning frequency layers are defined.

A PRS Resource Set is a collection of PRS resources across one TRP whichhave certain shared parameters, e.g.:

-   -   Same periodicity (e.g., 2^(m){4, 5, 8, 10, 16, 20, 32, 40, 64,        80, 160, 320, 640, 1280, 2560, 5120, 10240} slots, with p=0, 1,        2, 3,    -   A common muting pattern configuration, and    -   Same repetition factor across slots, (e.g., values {1, 2, 4, 6,        8, 16, 32} slots).

Examples of DL PRS resource set patterns may be configured with the comband symbol pairings depicted in Table 3, as follows:

TABLE 3 2 symbols 4 symbols 6 symbols 12 symbols Comb-2 {0, 1} {0, 1, 0,1} {0, 1, 0, 1, 0, 1} {0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1} Comb-4 NA {0,2, 1, 3} NA {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3}} Comb-6 NA NA {0, 3, 1,4, 2, 5} {0, 3, 1, 4, 2, 5, 0, 3, 1, 4, 2, 5} Comb-12 NA NA NA {0, 6, 3,9, 1, 7, 4, 10, 2, 8, 5, 11}

Referring to Table 3, a DL PRS resource within a slot may span 2, 4, 6,or 12 consecutive symbols with a fully frequency-domain staggeredpattern. The DL PRS resource may be configured in any high-layerconfigured DL symbol of a slot. In some designs, an energy per resourceelement (EPRE) for all resource elements (REs) of a given DL PRSresource is constant.

In some designs, the modeling of UE power consumption for positioningmay be based upon the 3GPP-defined modeling for radio resourcemanagement (RRM) UE power consumption, whereby the UE monitors Nffrequency layers within a measurement gap, e.g.:

$\begin{matrix}{{E3} = {\left( {\sum\limits_{i = 0}^{{Nf} - 1}E_{i}} \right) + {{Et} \cdot \left( {{Nf} + 1} \right)}}} & \underset{\_}{{Equation}\mspace{14mu} 1}\end{matrix}$

where Ei is P_(fri)*Ns for each frequency layer i, Ns is the number ofslot over which measurements (for each frequency layer i) are carriedout, Nf is the number of frequency layers measured, Et=Pt*Tt, where Ptis the switching power consumption, micro sleep power is assumed to bethe same for Pt, and Tt is 0.5 ms for FR1 and 0.25 ms for FR2 (from 3GPPRAN4 working group).

In some designs, the UE power consumption for positioning should factorat least, e.g.:

-   -   The number of positioning frequency layer,    -   The number of TRPs,    -   The number of symbols for each PRS resource,    -   The PRS bandwidth, and/or    -   The number of slots for PRS measurement.

As noted above, a UE may measure PRS from a number of TRPs inassociation with a position estimation procedure. A higher number ofTRPs associated with a positioning procedure generally results in higherpower consumption at the UE.

In some designs, some or all of a DL PRS Resource Set may be “muted” (orskipped) to mitigate interference. For example, muting may beimplemented to offset an increase to interference caused by a highernumber of TRPs transmitting the DL-PRS. In some designs, a bitmap for DLPRS muting is configured for a DL PRS Resource Set. The followingoptions are supported for the applicability of the bitmap, e.g.:

-   -   Option 1: Each bit in the bitmap corresponds to a configurable        number of consecutive instances (in a periodic transmission of        DL-PRS resource sets) of a DL-PRS Resource set. All DL-PRS        Resources within a DL-PRS Resource Set instance are muted for a        DL-PRS Resource Set instance that is indicated to be muted by        the bitmap    -   Option 2: Each bit in the bitmap corresponds to a single        repetition index for each of the DL-PRS Resources within an        instance of a DL-PRS Resource Set (the length of the bitmap is        equal to DL-PRS-ResourceRepetitionFactor). In some designs, the        bitmap is applicable to all instances of the DL-PRS Resource        Set.

In some designs, the size of a bitmap for DL PRS muting may be 2, 4, 8,16 or 32 bits.

FIG. 10 illustrates a PRS muting scheme 1000 in accordance with anaspect of the disclosure. In particular, the PRS muting scheme 1000 isan example of an Option 1 PRS muting scheme with comb-2, 2-symbol withrepetition of 2, with 2 bits in the muting bitmap. Referring to FIG. 10,there are a total of 4 TRPs, denoted as 1, 2, 3 and 4.

Referring to FIG. 10, TRPs 1 and 2 are FDMed using comb-2, and TRPs 3and 4 are FDMed using comb-2. Each TRP transmits a PRS ofcomb-2/2-symbol with repetition of 2 in consecutive slots 0-1 per PRSperiod or T_(PRS). Each TRP is configured with a 2-bit bitmap (each bitcorresponds to each of the 2 occasions). If the bit is 1, then the TRPtransmits in that occasion; otherwise, all repetitions of that specificoccasion are muted. For PRS muting scheme 1000 in accordance with Option1, the UE needs to receive both occasions to get a “clean copy” of allTRPs. This is because, in the 1^(st) occasion, only TRPs 1-2 transmit inboth repetitions while TRPs 3-4 are muted, and in the 2^(nd) PRSoccasion, only TRPs 3-4 transmit in both repetitions, while TRPs 1-2 aremuted.

FIG. 11 illustrates a PRS muting scheme 1100 in accordance with anaspect of the disclosure. In particular, the PRS muting scheme 1100 isan example of an Option 2 PRS muting scheme with comb-2, 2-symbol withrepetition of 2, with 2 bits in the muting bitmap. Referring to FIG. 11,there are a total of 4 TRPs, denoted as 1, 2, 3 and 4.

Referring to FIG. 11, TRPs 1 and 2 are FDMed using comb-2, and TRPs 3and 4 are FDMed using comb-2. Each TRP transmits a PRS ofcomb-2/2-symbol with repetition of 2 in consecutive slots 0-1 per PRSperiod or T_(PRS). Each TRP is configured with a 2-bit bitmap (each bitcorresponds to each of the 2 occasions). If the bit is 1, then the TRPtransmits in that repetition index; otherwise, that repetition index ismuted. For PRS muting scheme 1100 in accordance with Option 2, the UEreceives clean copies of all 4 TRPs in a single occasion (since in thefirst repetition TRPs 1 and 2 transmit FDMed PRS with TRPs 3-4 muted,and in the 2^(nd) repetition, TRPs 3 and 4 transmit FDMed PRS but TRPs1-2 are muted).

Referring to FIGS. 10-11, in Option 2, within one occasion, each TRP isconfigured with a PRS with repetitions, some of which are mutedaccording to the muting bitmap (e.g., up to 32 bits, since we have up to32 repetition length of one occasion). In Option 1, within an occasion,all repetitions of a TRP are muted or not, and the bitmap (e.g., up to32 bits) is used to control the muting across occasions. In this case,the UE may not receive any PRS from a specific TRP in a particularoccasion, but will receive in next occasion.

Aspects of the disclosure are directed to configuring base station(s)(e.g., one or more neighbor base stations) to monitor RTT-relatedsignaling that is exchanged between a UE and a different base station(e.g., a serving base station). The monitored RTT-related signaling maybe processed so as to estimate RTT between the UE and the basestation(s) without the UE being required to measure PRS from those basestation(s). Such aspects may provide various technical advantages, suchas reducing power consumption at the UE and decreasing physical-layerpositioning latency.

FIG. 12A illustrates an exemplary process 1200A of wirelesscommunication, according to aspects of the disclosure. In an aspect, theprocess 1200A may be performed by a first base station, which may beconfigured as described above with respect to BS 304.

At 1210A, the first base station (e.g., receiver 352, receiver 362,positioning measurement module 388, etc.) measures a SRS-P associatedwith a RTT measurement procedure between a UE and a second base station.In some designs, the second base station is configured as a serving basestation of the UE, and the first base station is a neighboring basestation of the UE. In some designs, the first base station may alsomeasure a PRS associated with the RTT measurement procedure (e.g.,either preceding or following the SRS-P). However, in some designs, thepropagation delay from the second base station to the first base stationas well as the PRS transmission time may already be known to the network(e.g., from an earlier RS measurement procedure between the first andsecond base stations), in which case the PRS ToA associated with the RTTmeasurement procedure at the second base station could be estimatedrather than measured by the first base station.

At 1220A, the first base station (e.g., transmitter 354, transmitter364, network interface(s) 380, etc.) reports measurement informationbased on the measurement of the SRS-P. In some designs, the measurementinformation may be reported to an entity that may use the measurementinformation to facilitate position estimation of the UE, such as the UEitself, the second base station, a LMF component, or a combinationthereof (e.g., LMF may be integrated with the second base station). Insome designs, the measurement information may comprise a differencebetween the ToA (as measured at the first base station) of the SRS-Pfrom the UE and the ToA (as measured or estimated at the first basestation) of the PRS from the second base station. In other designs, themeasurement information may comprise information by which theabove-noted ToA differential can be derived (e.g., the respective ToAsrather than their calculated differential, or only the SRS-P ToA withthe PRS ToA capable of being estimated from a known propagation delaybetween the base stations and a known PRS transmission time as notedabove).

FIG. 12B illustrates an exemplary process 1200B of wirelesscommunication, according to aspects of the disclosure. In an aspect, theprocess 1200B may be performed by a first base station, which may beconfigured as described above with respect to BS 304. The process 1200Balso corresponds to an example implementation of the process 1200A ofFIG. 12A, except that BS 304 more specifically determines (e.g., viacalculation or measurement) and reports a ToA of the PRS in the process1200B, which by contrast is optional in the process 1200A.

At 1210B, the first base station (e.g., receiver 352, receiver 362,positioning measurement module 388, etc.) measures a SRS-P associatedwith a RTT measurement procedure between a UE and a second base station.In some designs, the second base station is configured as a serving basestation of the UE, and the first base station is a neighboring basestation of the UE.

At 1220B, the first base station (e.g., receiver 352, receiver 362,positioning measurement module 388, processing system 384, etc.)determines a time of arrival (ToA) at the first base station of apositioning reference signal (PRS) associated with the RTT measurementprocedure between the UE and the second base station. As noted above.the first base station may determine the ToA of the PRS by measuring thePRS itself (e.g., either preceding or following the SRS-P). However, insome designs, the propagation delay from the second base station to thefirst base station as well as the PRS transmission time may already beknown to the first base station (e.g., from an earlier RS measurementprocedure between the first and second base stations), in which case thePRS ToA associated with the RTT measurement procedure at the second basestation could be estimated (via calculation) rather than measured by thefirst base station.

At 1230B, the first base station (e.g., transmitter 354, transmitter364, network interface(s) 380, etc.) reports measurement informationbased on the measurement of the SRS-P and the determined ToA of the PRS.In some designs, the measurement information may be reported to anentity that may use the measurement information to facilitate positionestimation of the UE, such as the UE itself, the second base station, aLMF component, or a combination thereof (e.g., LMF may be integratedwith the second base station). In some designs, the measurementinformation may comprise a difference between the ToA (as measured atthe first base station) of the SRS-P from the UE and the ToA (asmeasured or estimated at the first base station) of the PRS from thesecond base station. In other designs, the measurement information maycomprise information by which the above-noted ToA differential can bederived (e.g., the respective ToAs rather than their calculateddifferential). 1230B of FIG. 12B may be contrasted with 1220A of FIG.12A, where the PRS ToA-based reporting is optional.

FIG. 13A illustrates an exemplary process 1300A of wirelesscommunication, according to aspects of the disclosure. In an aspect, theprocess 1300A may be performed by a device, such as a UE (e.g., UE 302),a BS (e.g., BS 304), an LMF component (e.g., network entity 306), or acombination thereof (e.g., LMF may be integrated with the BS).

At 1310A, the device (e.g., receiver 312, receiver 322, receiver 352,receiver 362, network interface(s) 380, network interface(s) 390, etc.)obtains first measurement information, based on one or more measurementsby at least one first base station, related to both a PRS associatedwith a round-trip time (RTT) measurement procedure between a userequipment (UE) and a second base station and a sounding reference signalfor positioning (SRS-P) from the UE. In some designs, multiple BSs maybe configured to monitor the SRS-P from the UE (e.g., in associationwith RTT measurement between the UE and each respective BS). Forexample, the first measurement information at 1310A may include themeasurement information reported by the first base station at 1220A ofFIG. 12A or 1230B of FIG. 12B. As noted above, in some designs, eachrespective first base station may provide a time differential between aToA of the SRS-P at the respective first base station and a ToA of thePRS at the respective first base station (e.g., as in FIG. 12B).However, in other designs, each respective first base station mayinstead provide information sufficient for estimation of the timedifferential (e.g., such as SRS-P ToA, with the PRS ToA at therespective first base station being derivable from a known PRStransmission time and a known propagation time from the second basestation to the respective first base station).

At 1320A, the device (e.g., receiver 312, receiver 322, receiver 352,receiver 362, network interface(s) 380, network interface(s) 390, etc.)obtains second measurement information, based on one or moremeasurements at the UE, related to the PRS associated with the RTTmeasurement procedure. For example, the second measurement informationmay comprise a Rx-Tx measurement (e.g., t₃−t₂) if the UE is responderfor the RTT measurement procedure, or a Tx-Rx measurement (e.g., t₄−t₁)if the UE is initiator for the RTT measurement procedure.

At 1330A, the device (e.g., receiver 312, receiver 322, receiver 352,receiver 362, network interface(s) 380, network interface(s) 390, etc.)obtains third measurement information, based on one or more measurementsat the second base station, related to the SRS-P associated with the RTTprocedure. For example, the second measurement information may comprisea Rx-Tx measurement (e.g., t₃−t₂) if the second base station isresponder for the RTT measurement procedure, or a Tx-Rx measurement(e.g., t₄−t₁) if the second base station is initiator for the RTTmeasurement procedure.

At 1340A, the device (e.g., processing system 332 or 384 or 394,positioning measurement module 342 or 388 or 389, etc.) determines apositioning estimate of the UE based on the first, second and thirdmeasurement information. Various examples by which the positioningestimate can be determined at 1340A are described below in detail.

FIG. 13B illustrates an exemplary process 1300B of wirelesscommunication, according to aspects of the disclosure. In an aspect, theprocess 1300B may be performed by a device, such as a UE (e.g., UE 302),a BS (e.g., BS 304), an LMF component (e.g., network entity 306), or acombination thereof (e.g., LMF may be integrated with the BS). Theprocess 1300B also corresponds to an example implementation of theprocess 1300A of FIG. 13A, except that the device more specificallyreceives the PRS and SRS-P related measurement information from the atleast one first base station, which by contrast is optional in theprocess 1300A (e.g., because at least PRS-related information may becalculated/derived at the device in the process 1300A).

At 1310B, the device (e.g., receiver 312, receiver 322, receiver 352,receiver 362, network interface(s) 380, network interface(s) 390, etc.)receives, from at least one first base station, first measurementinformation related to both a PRS associated with a round-trip time(RTT) measurement procedure between a user equipment (UE) and a secondbase station and a sounding reference signal for positioning (SRS-P)from the UE. In some designs, multiple BSs may be configured to monitorthe SRS-P from the UE (e.g., in association with RTT measurement betweenthe UE and each respective BS). For example, the first measurementinformation at 1310B may include the measurement information reported bythe first base station at 1220A of FIG. 12A or 1230B of FIG. 12B. Asnoted above, in some designs, each respective first base station mayprovide a time differential between a ToA of the SRS-P at the respectivefirst base station and a ToA of the PRS at the respective first basestation (e.g., as in FIG. 12B). As noted above, the ToA of the PRS mayeither be measured at the respective first base station orcalculated/derived at the respective first base station.

At 1320B, the device (e.g., receiver 312, receiver 322, receiver 352,receiver 362, network interface(s) 380, network interface(s) 390, etc.)obtains second measurement information, based on one or moremeasurements at the UE, related to the PRS associated with the RTTmeasurement procedure. For example, the second measurement informationmay comprise a Rx-Tx measurement (e.g., t₃−t₂) if the UE is responderfor the RTT measurement procedure, or a Tx-Rx measurement (e.g., t₄−t₁)if the UE is initiator for the RTT measurement procedure.

At 1330B, the device (e.g., receiver 312, receiver 322, receiver 352,receiver 362, network interface(s) 380, network interface(s) 390, etc.)obtains third measurement information, based on one or more measurementsat the second base station, related to the SRS-P associated with the RTTprocedure. For example, the second measurement information may comprisea Rx-Tx measurement (e.g., t₃−t₂) if the second base station isresponder for the RTT measurement procedure, or a Tx-Rx measurement(e.g., t₄−t₁) if the second base station is initiator for the RTTmeasurement procedure.

At 1340B, the device (e.g., processing system 332 or 384 or 394,positioning measurement module 342 or 388 or 389, etc.) determines apositioning estimate of the UE based on the first, second and thirdmeasurement information. Various examples by which the positioningestimate can be determined at 1340B are described below in detail.

FIG. 14 is a diagram 1400 showing exemplary timings of RTT measurementsignals exchanged between BSs 1-3 and a UE in accordance with an exampleimplementation of the processes 1200A-1300B of FIGS. 12A-13B. In somedesigns, each of BSs 1-3 may be configured as described above withrespect to BS 304, and the UE may be configured as described above withrespect to UE 302. In some designs, BS 1 is the serving BS of UE 302,and BSs 2-3 are neighboring base stations of UE 302.

In the example of FIG. 14, the procedure between BS 1 and UE 302 maycorrespond to the procedure described above with respect to FIG. 9.

In particular, BS 1 is the initiator of the RTT measurement procedure,while UE 302 is the responder. In some designs, this orientation (withBS 1 as initiator and UE 302 as responder) may be particularly suitedfor network-based positioning. Accordingly, BS 1 sends an RTTmeasurement signal 1410 (e.g., PRS, NRS, CRS, CSI-RS, etc.) to UE 302 attime t₁. The RTT measurement signal 1410 has some propagation delayT_(Prop,BS1→UE) as it travels from BS 1 to UE 302. At time t₂ (the ToAof the RTT measurement signal 1410 at UE 302), UE 302 receives/measuresthe RTT measurement signal 1410. After some UE processing time, UE 302transmits an RTT response signal 1420 at time t₃. After the propagationdelay T_(Prop,UE→BS1), BS 1 receives/measures the RTT response signal1420 from UE 302 at time t₄ (the ToA of the RTT response signal 1420 atBS 1). The manner in which the RTT measurement signals can be measured(e.g., CER-based peak processing) has already been described above andis omitted here for the sake of brevity.

In some designs, the RTT response signal 1420 may explicitly include thedifference between time t₃ and time t₂ (i.e., T_(Rx→Tx) 1412). Usingthis measurement and the difference between time t₄ and time t₁ (i.e.,T_(Tx→Rx) 1422), BS 1 (or other positioning entity, such as locationserver 230, LMF 270) can calculate the distance to UE 302 as:

$d = {{\frac{1}{2c}\left( {T_{{Tx}\rightarrow{Rx}} - T_{{Rx}\rightarrow{Tx}}} \right)} = {{\frac{1}{2c}\left( {t_{2} - t_{1}} \right)} - {\frac{1}{2c}\left( {t_{4} - t_{3}} \right)}}}$

where c is the speed of light. While not illustrated expressly in FIG.14, an additional source of delay or error may be due to UE and gNBhardware group delay for position location.

Referring to FIG. 14, the same RTT measurement signal 1410 measured byUE 302 at t₂ also has some propagation delay T_(Prop,BS1→BS2) as ittravels from BS 1 to BS 2. BS 2 receives/measures the RTT measurementsignal 1410. The same RTT measurement signal 1420 measured by BS 1 at t₄also has some propagation delay T_(Prop,UE→BS2) as it travels from UE302 to BS 2. BS 2 receives/measures the RTT measurement signal 1420. Thetime differential between the ToAs of the RTT measurement signal 1410and the RTT measurement signal 1420 as measured at BS 2 can then bereported as T_(Rx→Rx) 1430. It will be appreciated that T_(Rx→Rx) 1430corresponds to a time differential between two receptions (Rx) incontrast to 1412 or 1422 which each correspond to a time differentialbetween a reception (Rx) and a transmission (Tx). As noted above, inother designs, T_(Prop,BS1→BS2) may be known in advance (e.g., from anearlier RS exchange/measurement), in which case the ToA of the RTTmeasurement signal 1410 at BS 2 can be estimated rather than measured(e.g., by BS 2 or some other entity).

Referring to FIG. 14, the same RTT measurement signal 1410 measured byUE 302 at t₂ also has some propagation delay T_(Prop,BS1→BS3) as ittravels from BS 1 to BS 3. BS 3 receives/measures the RTT measurementsignal 1410. The same RTT measurement signal 1420 measured by BS 1 at t₄also has some propagation delay T_(Prop,UE→BS3) as it travels from UE302 to BS 3. BS 3 receives/measures the RTT measurement signal 1420. Thetime differential between the ToAs of the RTT measurement signal 1410and the RTT measurement signal 1420 as measured at BS 3 can then bereported as T_(Rx→Rx) 1440. Similar to T_(Rx→Rx) 1430, it will beappreciated that T_(Rx→Rx) 1440 corresponds to a time differentialbetween two receptions (Rx) in contrast to 1412 or 1422 which eachcorrespond to a time differential between a reception (Rx) and atransmission (Tx). As noted above, in other designs, T_(Prop,BS1→BS3)may be known in advance (e.g., from an earlier RS exchange/measurement),in which case the ToA of the RTT measurement signal 1410 at BS 3 can beestimated rather than measured (e.g., by BS 3 or some other entity).

While FIG. 14 depicts an example where two BSs perform T_(Rx→Rx)measurements, the number of BSs that may perform the T_(Rx→Rx)measurement is scalable (e.g., 1, 3, 4, etc.). In some designs as notedabove, BS 1 may correspond to the serving gNB of UE 302 (e.g., becauseUE 302 is synchronized with its serving cell, which may improve themeasurement quality). However, BS 1 may correspond to any gNB (e.g.,serving base station or neighboring base station) in other designs,which may be configured by LMF. In some designs, UE 302 may transmitT_(Rx→Tx) 1412 to the LMF via BS 1. In some designs, BS 1 may transmitT_(Tx→Rx) 1422 to the LMF. In some designs, BS 2 may transmit T_(Rx→Rx)1430 to the LMF, and BS 3 may transmit T_(Rx→Rx) 1440 to the LMF.

In some designs, the propagation distance (T_(Prop,UE→BS2) andT_(Prop,UE→BS3)) between UE 302 and BS 2 or BS 3 may be calculated, asshown below with respect to BS 2 (T_(Prop,UE→BS2)) by way of example:

T _(Prop,BS1→UE) +T _(Rx→Tx) 1412+T _(Prop,UE→BS2) =T _(Prop,BS1→BS2) +T_(Rx→Rx) 1430   Equation 2

In Equation 2, T_(Prop,UE→BS2) and T_(Prop,BS1→BS2) are unknowns.However, T_(Prop,BS1→BS2) can be determined in a variety of ways. Forexample, the network may have accurate information of the locations ofBS 1 and BS 2, from which T_(Prop,BS1→BS2) can be derived. In anotherexample, GPS reports from BS 1 and BS 2 can be used to deriveT_(Prop,BS1→BS2). In another example, NR-based positioning with PRStransmission/reception between BS 1 and BS 2 can be used to deriveT_(Prop,BS1→BS2). Once T_(Prop,BS1→BS2) is known, Equation 2 can be usedto solve for T_(Prop,UE→BS2).

In accordance with FIG. 14, a single PRS procedure from the UEperspective is used to obtain multiple propagation distance estimationsbased on a multi-RTT based positioning procedure. Because the UE needonly measure PRS from a single gNB, both positioning latency and UEpower consumption can be reduced. In other designs, multiple PRSprocedures from the UE perspective may be performed (e.g., multipleanchor BSs for active PRS measurement at UE, with at least one anchor BSbeing associated with one or more secondary BSs that perform theT_(Rx→Rx) measurement using the RTT measurement signals for a respectiveanchor BS).

FIG. 15 is a diagram 1500 showing exemplary timings of RTT measurementsignals exchanged between BSs 1-3 and a UE in accordance with anotherexample implementation of the processes 1200A-1300B of FIGS. 12A-13B. Insome designs, each of BSs 1-3 may be configured as described above withrespect to BS 304, and the UE may be configured as described above withrespect to UE 302. In some designs, BS 1 is the serving BS of UE 302,and BSs 2-3 are neighboring base stations of UE 302.

In contrast to FIG. 14, UE 302 is the initiator of the RTT measurementprocedure, while BS 1 is the responder. In some designs, thisorientation (with UE 302 as initiator and BS 1 as responder) may beparticularly suited for UE-based positioning. Accordingly, UE 302 sendsan RTT measurement signal 1510 (e.g., SRS-P, etc.) to BS 1 at time t₁.The RTT measurement signal 1510 has some propagation delayT_(Prop,UE→BS1) as it travels from UE 302 to BS 1. At time t₂ (the ToAof the RTT measurement signal 1510 at BS 1), BS 1 receives/measures theRTT measurement signal 1510. After some BS processing time, BS 1transmits an RTT response signal 1520 at time t₃. After the propagationdelay T_(Prop,BS1→UE), UE 302 receives/measures the RTT response signal1520 from BS 1 at time t₄ (the ToA of the RTT response signal 1520 at UE302). The manner in which the RTT measurement signals can be measured(e.g., CER-based peak processing) has already been described above andis omitted here for the sake of brevity.

In some designs, the RTT response signal 1520 may explicitly include thedifference between time t₃ and time t₂ (i.e., T_(Rx→Tx) 1512). Usingthis measurement and the difference between time t₄ and time t₁ (i.e.,T_(Tx→Rx) 1522), UE 302 (or other positioning entity, such as locationserver 230, LMF 270) can calculate the distance to BS 1 as:

$d = {{\frac{1}{2c}\left( {T_{{Tx}\rightarrow{Rx}} - T_{{Rx}\rightarrow{Tx}}} \right)} = {{\frac{1}{2c}\left( {t_{2} - t_{1}} \right)} - {\frac{1}{2c}\left( {t_{4} - t_{3}} \right)}}}$

where c is the speed of light. While not illustrated expressly in FIG.15, an additional source of delay or error may be due to UE and gNBhardware group delay for position location.

Referring to FIG. 15, the same RTT measurement signal 1510 measured byBS 1 at t₂ also has some propagation delay T_(Prop,UE→BS2) as it travelsfrom UE 302 to BS 2. BS 2 receives/measures the RTT measurement signal1510. The same RTT response signal 1520 measured by UE 302 at t₄ alsohas some propagation delay T_(Prop,BS1→BS2) as it travels from BS 1 toBS 2. BS 2 receives/measures the RTT response signal 1520. The timedifferential between the ToAs of the RTT measurement signal 1510 and theRTT response signal 1520 as measured at BS 2 can then be reported asT_(Rx→Rx) 1530. It will be appreciated that T_(Rx→Rx) 1530 correspondsto a time differential between two receptions (Rx) in contrast to 1512or 1522 which each correspond to a time differential between a reception(Rx) and a transmission (Tx). As noted above, in other designs,T_(Prop,BS1→BS2) may be known in advance (e.g., from an earlier RSexchange/measurement), in which case the ToA of the RTT response signal1520 at BS 2 can be estimated rather than measured (e.g., by BS 2 orsome other entity).

Referring to FIG. 15, the same RTT measurement signal 1510 measured byBS 1 at t₂ also has some propagation delay T_(Prop,UE→BS3) as it travelsfrom UE 302 to BS 3. BS 3 receives/measures the RTT measurement signal1510. The same RTT response signal 1520 measured by UE 302 at t₄ alsohas some propagation delay T_(Prop,BS1→BS3) as it travels from BS 1 toBS 3. BS 3 receives/measures the RTT response signal 1520. The timedifferential between the ToAs of the RTT measurement signal 1510 and theRTT response signal 1520 as measured at BS 3 can then be reported asT_(Rx→Rx) 1540. It will be appreciated that T_(Rx→Rx) 1540 correspondsto a time differential between two receptions (Rx) in contrast to 1512or 1522 which each correspond to a time differential between a reception(Rx) and a transmission (Tx). As noted above, in other designs,T_(Prop,BS1→BS3) may be known in advance (e.g., from an earlier RSexchange/measurement), in which case the ToA of the RTT response signal1520 at BS 3 can be estimated rather than measured (e.g., by BS 3 orsome other entity).

While FIG. 15 depicts an example where two BSs perform T_(Rx→Rx)measurements, the number of BSs that may perform the T_(Rx→Rx)measurement is scalable (e.g., 1, 3, 4, etc.). In some designs as notedabove, BS 1 may correspond to the serving gNB of UE 302 (e.g., becauseUE 302 is synchronized with its serving cell, which may improve themeasurement quality). However, BS 1 may correspond to any gNB (e.g.,serving base station or neighboring base station) in other designs,which may be configured by LMF. In some designs, BS 1 may transmitT_(Rx→Tx) 1512 to UE 302, BS 2 may transmit T_(Rx→Rx) 1530 to UE 302,and BS 3 may transmit T_(Rx→Rx) 1540 to UE 302.

In some designs, the propagation distance (T_(Prop,UE→BS2) andT_(Prop,UE→BS3)) between UE 302 and BS 2 or BS 3 may be calculated, asshown below with respect to BS 2 (T_(Prop,UE→BS2)) by way of example:

T _(Prop,UE→BS1) +T _(Rx→Tx) 1512+T _(Prop,BS1→BS2) =T _(Prop,UE→BS2) +T_(Rx→Rx) 1530   Equation 3

In Equation 3, T_(Prop,UE→BS2) and T_(Prop,BS1→BS2) are unknowns.However, T_(Prop,BS1→BS2) can be determined in a variety of ways. Forexample, the network may have accurate information of the locations ofBS 1 and BS 2, from which T_(Prop,BS1→BS2) can be derived. In anotherexample, GPS reports from BS 1 and BS 2 can be used to deriveT_(Prop,BS1→BS2). In another example, NR-based positioning with PRStransmission/reception between BS 1 and BS 2 can be used to deriveT_(Prop,BS1→BS2). Once T_(Prop,BS1→BS2) is known, Equation 3 can be usedto solve for T_(Prop,UE→BS2).

In accordance with FIG. 15, a single PRS procedure from the UEperspective is used to obtain multiple propagation distance estimationsbased on a multi-RTT based positioning procedure. Because the UE needonly measure PRS from a single gNB, both positioning latency and UEpower consumption can be reduced. In other designs, multiple PRSprocedures from the UE perspective may be performed (e.g., multipleanchor BSs for active PRS measurement at UE, with at least one anchor BSbeing associated with one or more secondary BSs that perform theT_(Rx→Rx) measurement using the RTT measurement signals for a respectiveanchor BS).

Referring to FIGS. 14-15, it will be appreciated that the SRS-P followsthe PRS in FIG. 14, while the PRS follows the SRS-P in FIG. 15. Further,the ToA of the PRS in FIGS. 14-15 can either be measured or estimated(e.g., from known PRS transmission time and known BS-to-BS propagationdelay) as noted above.

In the detailed description above it can be seen that different featuresare grouped together in examples. This manner of disclosure should notbe understood as an intention that the example clauses have morefeatures than are explicitly mentioned in each clause. Rather, thevarious aspects of the disclosure may include fewer than all features ofan individual example clause disclosed. Therefore, the following clausesshould hereby be deemed to be incorporated in the description, whereineach clause by itself can stand as a separate example. Although eachdependent clause can refer in the clauses to a specific combination withone of the other clauses, the aspect(s) of that dependent clause are notlimited to the specific combination. It will be appreciated that otherexample clauses can also include a combination of the dependent clauseaspect(s) with the subject matter of any other dependent clause orindependent clause or a combination of any feature with other dependentand independent clauses. The various aspects disclosed herein expresslyinclude these combinations, unless it is explicitly expressed or can bereadily inferred that a specific combination is not intended (e.g.,contradictory aspects, such as defining an element as both an insulatorand a conductor). Furthermore, it is also intended that aspects of aclause can be included in any other independent clause, even if theclause is not directly dependent on the independent clause.

Implementation examples are described in the following numbered clauses:

Clause 1. A method of operating a first base station, comprising:measuring a sounding reference signal for positioning (SRS-P) associatedwith a round-trip time (RTT) measurement procedure between a userequipment (UE) and a second base station; and reporting measurementinformation based on the measurement of the SRS-P.

Clause 2. The method of clause 1, further comprising: measuring apositioning reference signal (PRS) associated with the RTT measurementprocedure.

Clause 3. The method of clause 2, wherein the measurement informationcomprises a difference between a first time of arrival (ToA) of theSRS-P at the first base station and a second ToA of the PRS at the firstbase station.

Clause 4. The method of any of clauses 2 to 3, wherein the PRS followsthe SRS-P, or wherein the SRS-P follows the PRS.

Clause 5. The method of any of clauses 1 to 4, wherein the reportedmeasurement information comprises a time of arrival (ToA) of the SRS-P.

Clause 6. The method of any of clauses 1 to 5, wherein the measurementinformation comprises a difference between a first time of arrival (ToA)of the SRS-P at the first base station and a second ToA of a positioningreference signal (PRS) at the first base station.

Clause 7. The method of clause 6, wherein the ToA of the PRS at thefirst base station is estimated based on a known time of PRStransmission and a known propagation delay between the first basestation and the second base station.

Clause 8. The method of any of clauses 1 to 7, wherein the reportingreports the measurement information to the UE, the first base station, alocation management function (LMF) component, or a combination thereof.

Clause 9. A method of operating a device, comprising: obtaining firstmeasurement information, based on one or more measurements by at leastone first base station, related to both a positioning reference signal(PRS) associated with a round-trip time (RTT) measurement procedurebetween a user equipment (UE) and a second base station and a soundingreference signal for positioning (SRS-P) from the UE; obtaining secondmeasurement information, based on one or more measurements at the UE,related to the PRS associated with the RTT measurement procedure;obtaining third measurement information, based on one or moremeasurements at the second base station, related to the SRS-P associatedwith the RTT procedure; and determining a positioning estimate of the UEbased on the first, second and third measurement information.

Clause 10. The method of clause 9, wherein the at least one first basestation comprises a single base station, or wherein the at least onefirst base station comprises a plurality of base stations.

Clause 11. The method of any of clauses 9 to 10, wherein the firstmeasurement information is further based on one or more additionalmeasurements by the at least one first base station related to the PRSassociated with the RTT procedure.

Clause 12. The method of clause 11, wherein the first measurementinformation comprises a difference between a first time of arrival (ToA)of the SRS-P at the at least one first base station and a second ToA ofthe PRS at the at least one first base station.

Clause 13. The method of any of clauses 9 to 12, wherein the PRS followsthe SRS-P, or wherein the SRS-P follows the PRS.

Clause 14. The method of any of clauses 9 to 13, wherein the firstmeasurement information comprises a time of arrival (ToA) of the SRS-P.

Clause 15. The method of any of clauses 9 to 14, wherein the firstmeasurement information comprises a difference between a first time ofarrival (ToA) of the SRS-P at the at least one first base station and asecond ToA of the PRS at the at least one first base station.

Clause 16. The method of clause 15, wherein the ToA of the PRS at the atleast one first base station is estimated based on a known time of PRStransmission and at least one known propagation delay between the atleast one first base station and the second base station.

Clause 17. The method of any of clauses 9 to 16, wherein the devicecorresponds to the UE, the first base station, a location managementfunction (LMF) component, or a combination thereof.

Clause 18. A first base station, comprising: a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: measure a sounding reference signal for positioning(SRS-P) associated with a round-trip time (RTT) measurement procedurebetween a user equipment (UE) and a second base station; and reportmeasurement information based on the measurement of the SRS-P.

Clause 19. The first base station of clause 18, wherein the at least oneprocessor is further configured to: measure a positioning referencesignal (PRS) associated with the RTT measurement procedure.

Clause 20. The first base station of clause 19, wherein the measurementinformation comprises a difference between a first time of arrival (ToA)of the SRS-P at the first base station and a second ToA of the PRS atthe first base station.

Clause 21. The first base station of any of clauses 19 to 20, whereinthe PRS follows the SRS-P, or wherein the SRS-P follows the PRS.

Clause 22. The first base station of any of clauses 18 to 21, whereinthe reported measurement information comprises a time of arrival (ToA)of the SRS-P.

Clause 23. The first base station of any of clauses 18 to 22, whereinthe measurement information comprises a difference between a first timeof arrival (ToA) of the SRS-P at the first base station and a second ToAof a positioning reference signal (PRS) at the first base station.

Clause 24. The first base station of clause 23, wherein the ToA of thePRS at the first base station is estimated based on a known time of PRStransmission and a known propagation delay between the first basestation and the second base station.

Clause 25. The first base station of any of clauses 18 to 24, whereinthe reporting reports the measurement information to the UE, the firstbase station, a location management function (LMF) component, or acombination thereof.

Clause 26. A device, comprising: a memory; at least one transceiver; andat least one processor communicatively coupled to the memory and the atleast one transceiver, the at least one processor configured to: obtainfirst measurement information, based on one or more measurements by atleast one first base station, related to both a positioning referencesignal (PRS) associated with a round-trip time (RTT) measurementprocedure between a user equipment (UE) and a second base station and asounding reference signal for positioning (SRS-P) from the UE; obtainsecond measurement information, based on one or more measurements at theUE, related to the PRS associated with the RTT measurement procedure;obtain third measurement information, based on one or more measurementsat the second base station, related to the SRS-P associated with the RTTprocedure; and determine a positioning estimate of the UE based on thefirst, second and third measurement information.

Clause 27. The device of clause 26, wherein the at least one first basestation comprises a single base station, or wherein the at least onefirst base station comprises a plurality of base stations.

Clause 28. The device of any of clauses 26 to 27, wherein the firstmeasurement information is further based on one or more additionalmeasurements by the at least one first base station related to the PRSassociated with the RTT procedure.

Clause 29. The device of clause 28, wherein the first measurementinformation comprises a difference between a first time of arrival (ToA)of the SRS-P at the at least one first base station and a second ToA ofthe PRS at the at least one first base station.

Clause 30. The device of any of clauses 26 to 29, wherein the PRSfollows the SRS-P, or wherein the SRS-P follows the PRS.

Clause 31. The device of any of clauses 26 to 30, wherein the firstmeasurement information comprises a time of arrival (ToA) of the SRS-P.

Clause 32. The device of any of clauses 26 to 31, wherein the firstmeasurement information comprises a difference between a first time ofarrival (ToA) of the SRS-P at the at least one first base station and asecond ToA of the PRS at the at least one first base station.

Clause 33. The device of clause 32, wherein the ToA of the PRS at the atleast one first base station is estimated based on a known time of PRStransmission and at least one known propagation delay between the atleast one first base station and the second base station.

Clause 34. The device of any of clauses 26 to 33, wherein the devicecorresponds to the UE, the first base station, a location managementfunction (LMF) component, or a combination thereof.

Clause 35. A first base station, comprising: means for measuring asounding reference signal for positioning (SRS-P) associated with around-trip time (RTT) measurement procedure between a user equipment(UE) and a second base station; and means for reporting measurementinformation based on the measurement of the SRS-P.

Clause 36. The first base station of clause 35, further comprising:means for measuring a positioning reference signal (PRS) associated withthe RTT measurement procedure.

Clause 37. The first base station of clause 36, wherein the measurementinformation comprises a difference between a first time of arrival (ToA)of the SRS-P at the first base station and a second ToA of the PRS atthe first base station.

Clause 38. The first base station of any of clauses 36 to 37, whereinthe PRS follows the SRS-P, or wherein the SRS-P follows the PRS.

Clause 39. The first base station of any of clauses 35 to 38, whereinthe reported measurement information comprises a time of arrival (ToA)of the SRS-P.

Clause 40. The first base station of any of clauses 35 to 39, whereinthe measurement information comprises a difference between a first timeof arrival (ToA) of the SRS-P at the first base station and a second ToAof a positioning reference signal (PRS) at the first base station.

Clause 41. The first base station of clause 40, wherein the ToA of thePRS at the first base station is estimated based on a known time of PRStransmission and a known propagation delay between the first basestation and the second base station.

Clause 42. The first base station of any of clauses 35 to 41, whereinthe reporting reports the measurement information to the UE, the firstbase station, a location management function (LMF) component, or acombination thereof.

Clause 43. A device, comprising: means for obtaining first measurementinformation, based on one or more measurements by at least one firstbase station, related to both a positioning reference signal (PRS)associated with a round-trip time (RTT) measurement procedure between auser equipment (UE) and a second base station and a sounding referencesignal for positioning (SRS-P) from the UE; means for obtaining secondmeasurement information, based on one or more measurements at the UE,related to the PRS associated with the RTT measurement procedure; meansfor obtaining third measurement information, based on one or moremeasurements at the second base station, related to the SRS-P associatedwith the RTT procedure; and means for determining a positioning estimateof the UE based on the first, second and third measurement information.

Clause 44. The device of clause 43, wherein the at least one first basestation comprises a single base station, or wherein the at least onefirst base station comprises a plurality of base stations.

Clause 45. The device of any of clauses 43 to 44, wherein the firstmeasurement information is further based on one or more additionalmeasurements by the at least one first base station related to the PRSassociated with the RTT procedure.

Clause 46. The device of clause 45, wherein the first measurementinformation comprises a difference between a first time of arrival (ToA)of the SRS-P at the at least one first base station and a second ToA ofthe PRS at the at least one first base station.

Clause 47. The device of any of clauses 43 to 46, wherein the PRSfollows the SRS-P, or wherein the SRS-P follows the PRS.

Clause 48. The device of any of clauses 43 to 47, wherein the firstmeasurement information comprises a time of arrival (ToA) of the SRS-P.

Clause 49. The device of any of clauses 43 to 48, wherein the firstmeasurement information comprises a difference between a first time ofarrival (ToA) of the SRS-P at the at least one first base station and asecond ToA of the PRS at the at least one first base station.

Clause 50. The device of clause 49, wherein the ToA of the PRS at the atleast one first base station is estimated based on a known time of PRStransmission and at least one known propagation delay between the atleast one first base station and the second base station.

Clause 51. The device of any of clauses 43 to 50, wherein the devicecorresponds to the UE, the first base station, a location managementfunction (LMF) component, or a combination thereof.

Clause 52. A non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a first basestation, cause the first base station to: measure a sounding referencesignal for positioning (SRS-P) associated with a round-trip time (RTT)measurement procedure between a user equipment (UE) and a second basestation; and report measurement information based on the measurement ofthe SRS-P.

Clause 53. The non-transitory computer-readable medium of clause 52,wherein the one or more instructions further cause the first basestation to: measure a positioning reference signal (PRS) associated withthe RTT measurement procedure.

Clause 54. The non-transitory computer-readable medium of clause 53,wherein the measurement information comprises a difference between afirst time of arrival (ToA) of the SRS-P at the first base station and asecond ToA of the PRS at the first base station.

Clause 55. The non-transitory computer-readable medium of any of clauses53 to 54, wherein the PRS follows the SRS-P, or wherein the SRS-Pfollows the PRS.

Clause 56. The non-transitory computer-readable medium of any of clauses52 to 55, wherein the reported measurement information comprises a timeof arrival (ToA) of the SRS-P.

Clause 57. The non-transitory computer-readable medium of any of clauses52 to 56, wherein the measurement information comprises a differencebetween a first time of arrival (ToA) of the SRS-P at the first basestation and a second ToA of a positioning reference signal (PRS) at thefirst base station.

Clause 58. The non-transitory computer-readable medium of clause 57,wherein the ToA of the PRS at the first base station is estimated basedon a known time of PRS transmission and a known propagation delaybetween the first base station and the second base station.

Clause 59. The non-transitory computer-readable medium of any of clauses52 to 58, wherein the reporting reports the measurement information tothe UE, the first base station, a location management function (LMF)component, or a combination thereof.

Clause 60. A non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a device, causethe device to: obtain first measurement information, based on one ormore measurements by at least one first base station, related to both apositioning reference signal (PRS) associated with a round-trip time(RTT) measurement procedure between a user equipment (UE) and a secondbase station and a sounding reference signal for positioning (SRS-P)from the UE; obtain second measurement information, based on one or moremeasurements at the UE, related to the PRS associated with the RTTmeasurement procedure; obtain third measurement information, based onone or more measurements at the second base station, related to theSRS-P associated with the RTT procedure; and determine a positioningestimate of the UE based on the first, second and third measurementinformation.

Clause 61. The non-transitory computer-readable medium of clause 60,wherein the at least one first base station comprises a single basestation, or wherein the at least one first base station comprises aplurality of base stations.

Clause 62. The non-transitory computer-readable medium of any of clauses60 to 61, wherein the first measurement information is further based onone or more additional measurements by the at least one first basestation related to the PRS associated with the RTT procedure.

Clause 63. The non-transitory computer-readable medium of clause 62,wherein the first measurement information comprises a difference betweena first time of arrival (ToA) of the SRS-P at the at least one firstbase station and a second ToA of the PRS at the at least one first basestation.

Clause 64. The non-transitory computer-readable medium of any of clauses60 to 63, wherein the PRS follows the SRS-P, or wherein the SRS-Pfollows the PRS.

Clause 65. The non-transitory computer-readable medium of any of clauses60 to 64, wherein the first measurement information comprises a time ofarrival (ToA) of the SRS-P.

Clause 66. The non-transitory computer-readable medium of any of clauses60 to 65, wherein the first measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at the atleast one first base station and a second ToA of the PRS at the at leastone first base station.

Clause 67. The non-transitory computer-readable medium of clause 66,wherein the ToA of the PRS at the at least one first base station isestimated based on a known time of PRS transmission and at least oneknown propagation delay between the at least one first base station andthe second base station.

Clause 68. The non-transitory computer-readable medium of any of clauses60 to 67, wherein the device corresponds to the UE, the first basestation, a location management function (LMF) component, or acombination thereof.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the aspects disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a DSP, an ASIC, an FPGA, orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described herein. A general purpose processor maybe a microprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,e.g., a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The methods, sequences and/or algorithms described in connection withthe aspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in random access memory (RAM), flashmemory, read-only memory (ROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An exemplary storage medium is coupled to the processor suchthat the processor can read information from, and write information to,the storage medium. In the alternative, the storage medium may beintegral to the processor. The processor and the storage medium mayreside in an ASIC. The ASIC may reside in a user terminal (e.g., UE). Inthe alternative, the processor and the storage medium may reside asdiscrete components in a user terminal.

In one or more exemplary aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects of thedisclosure, it should be noted that various changes and modificationscould be made herein without departing from the scope of the disclosureas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the aspects of the disclosuredescribed herein need not be performed in any particular order.Furthermore, although elements of the disclosure may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

What is claimed is:
 1. A method of operating a first base station,comprising: measuring a sounding reference signal for positioning(SRS-P) associated with a round-trip time (RTT) measurement procedurebetween a user equipment (UE) and a second base station; and reportingmeasurement information based on the measurement of the SRS-P.
 2. Themethod of claim 1, further comprising: measuring a positioning referencesignal (PRS) associated with the RTT measurement procedure.
 3. Themethod of claim 2, wherein the measurement information comprises adifference between a first time of arrival (ToA) of the SRS-P at thefirst base station and a second ToA of the PRS at the first basestation.
 4. The method of claim 2, wherein the PRS follows the SRS-P, orwherein the SRS-P follows the PRS.
 5. The method of claim 1, wherein thereported measurement information comprises a time of arrival (ToA) ofthe SRS-P.
 6. The method of claim 1, wherein the measurement informationcomprises a difference between a first time of arrival (ToA) of theSRS-P at the first base station and a second ToA of a positioningreference signal (PRS) at the first base station.
 7. The method of claim6, wherein the ToA of the PRS at the first base station is estimatedbased on a known time of PRS transmission and a known propagation delaybetween the first base station and the second base station.
 8. Themethod of claim 1, wherein the reporting reports the measurementinformation to the UE, the first base station, a location managementfunction (LMF) component, or a combination thereof.
 9. A method ofoperating a device, comprising: obtaining first measurement information,based on one or more measurements by at least one first base station,related to both a positioning reference signal (PRS) associated with around-trip time (RTT) measurement procedure between a user equipment(UE) and a second base station and a sounding reference signal forpositioning (SRS-P) from the UE; obtaining second measurementinformation, based on one or more measurements at the UE, related to thePRS associated with the RTT measurement procedure; obtaining thirdmeasurement information, based on one or more measurements at the secondbase station, related to the SRS-P associated with the RTT procedure;and determining a positioning estimate of the UE based on the first,second and third measurement information.
 10. The method of claim 9,wherein the at least one first base station comprises a single basestation, or wherein the at least one first base station comprises aplurality of base stations.
 11. The method of claim 9, wherein the firstmeasurement information is further based on one or more additionalmeasurements by the at least one first base station related to the PRSassociated with the RTT procedure.
 12. The method of claim 11, whereinthe first measurement information comprises a difference between a firsttime of arrival (ToA) of the SRS-P at the at least one first basestation and a second ToA of the PRS at the at least one first basestation.
 13. The method of claim 9, wherein the PRS follows the SRS-P,or wherein the SRS-P follows the PRS.
 14. The method of claim 9, whereinthe first measurement information comprises a time of arrival (ToA) ofthe SRS-P.
 15. The method of claim 9, wherein the first measurementinformation comprises a difference between a first time of arrival (ToA)of the SRS-P at the at least one first base station and a second ToA ofthe PRS at the at least one first base station.
 16. The method of claim15, wherein the ToA of the PRS at the at least one first base station isestimated based on a known time of PRS transmission and at least oneknown propagation delay between the at least one first base station andthe second base station.
 17. The method of claim 9, wherein the devicecorresponds to the UE, the first base station, a location managementfunction (LMF) component, or a combination thereof.
 18. A first basestation, comprising: a memory; at least one transceiver; and at leastone processor communicatively coupled to the memory and the at least onetransceiver, the at least one processor configured to: measure asounding reference signal for positioning (SRS-P) associated with around-trip time (RTT) measurement procedure between a user equipment(UE) and a second base station; and report measurement information basedon the measurement of the SRS-P.
 19. The first base station of claim 18,wherein the at least one processor is further configured to: measure apositioning reference signal (PRS) associated with the RTT measurementprocedure.
 20. The first base station of claim 19, wherein themeasurement information comprises a difference between a first time ofarrival (ToA) of the SRS-P at the first base station and a second ToA ofthe PRS at the first base station.
 21. The first base station of claim19, wherein the PRS follows the SRS-P, or wherein the SRS-P follows thePRS.
 22. The first base station of claim 18, wherein the reportedmeasurement information comprises a time of arrival (ToA) of the SRS-P.23. The first base station of claim 18, wherein the measurementinformation comprises a difference between a first time of arrival (ToA)of the SRS-P at the first base station and a second ToA of a positioningreference signal (PRS) at the first base station.
 24. The first basestation of claim 23, wherein the ToA of the PRS at the first basestation is estimated based on a known time of PRS transmission and aknown propagation delay between the first base station and the secondbase station.
 25. The first base station of claim 18, wherein thereporting reports the measurement information to the UE, the first basestation, a location management function (LMF) component, or acombination thereof.
 26. A device, comprising: a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: obtain first measurement information, based on one ormore measurements by at least one first base station, related to both apositioning reference signal (PRS) associated with a round-trip time(RTT) measurement procedure between a user equipment (UE) and a secondbase station and a sounding reference signal for positioning (SRS-P)from the UE; obtain second measurement information, based on one or moremeasurements at the UE, related to the PRS associated with the RTTmeasurement procedure; obtain third measurement information, based onone or more measurements at the second base station, related to theSRS-P associated with the RTT procedure; and determine a positioningestimate of the UE based on the first, second and third measurementinformation.
 27. The device of claim 26, wherein the at least one firstbase station comprises a single base station, or wherein the at leastone first base station comprises a plurality of base stations.
 28. Thedevice of claim 26, wherein the first measurement information is furtherbased on one or more additional measurements by the at least one firstbase station related to the PRS associated with the RTT procedure. 29.The device of claim 28, wherein the first measurement informationcomprises a difference between a first time of arrival (ToA) of theSRS-P at the at least one first base station and a second ToA of the PRSat the at least one first base station.
 30. The device of claim 26,wherein the PRS follows the SRS-P, or wherein the SRS-P follows the PRS.